diff --git a/app/controllers/instructeurs/dossiers_controller.rb b/app/controllers/instructeurs/dossiers_controller.rb
index f332392f0..74930bfcb 100644
--- a/app/controllers/instructeurs/dossiers_controller.rb
+++ b/app/controllers/instructeurs/dossiers_controller.rb
@@ -173,8 +173,6 @@ module Instructeurs
       if @commentaire.save
         @commentaire.dossier.update!(last_commentaire_updated_at: Time.zone.now)
         current_instructeur.follow(dossier)
-        # FIXME
-        mark_messagerie_as_read
         flash.notice = "Message envoyé"
         redirect_to messagerie_instructeur_dossier_path(procedure, dossier)
       else
diff --git a/app/controllers/instructeurs/procedures_controller.rb b/app/controllers/instructeurs/procedures_controller.rb
index e9eb91690..5d6f78834 100644
--- a/app/controllers/instructeurs/procedures_controller.rb
+++ b/app/controllers/instructeurs/procedures_controller.rb
@@ -169,6 +169,11 @@ module Instructeurs
 
       export = Export.find_or_create_export(export_format, groupe_instructeurs)
 
+      if export.ready? && export.old? && params[:force_export]
+        export.destroy
+        export = Export.find_or_create_export(export_format, groupe_instructeurs)
+      end
+
       if export.ready?
         respond_to do |format|
           format.js do
diff --git a/app/models/assign_to.rb b/app/models/assign_to.rb
index 82146a7d5..449159fb5 100644
--- a/app/models/assign_to.rb
+++ b/app/models/assign_to.rb
@@ -14,6 +14,8 @@
 #  procedure_id                                :integer
 #
 class AssignTo < ApplicationRecord
+  self.ignored_columns = [:procedure_id]
+
   belongs_to :instructeur, optional: false
   belongs_to :groupe_instructeur, optional: false
   has_one :procedure_presentation, dependent: :destroy
diff --git a/app/models/avis.rb b/app/models/avis.rb
index 8d52d9bf6..11e8256f5 100644
--- a/app/models/avis.rb
+++ b/app/models/avis.rb
@@ -9,13 +9,11 @@
 #  email                :string
 #  introduction         :text
 #  revoked_at           :datetime
-#  tmp_expert_migrated  :boolean          default(FALSE)
 #  created_at           :datetime         not null
 #  updated_at           :datetime         not null
 #  claimant_id          :integer          not null
 #  dossier_id           :integer
 #  experts_procedure_id :bigint
-#  instructeur_id       :integer
 #
 class Avis < ApplicationRecord
   include EmailSanitizableConcern
diff --git a/app/models/dossier.rb b/app/models/dossier.rb
index 2441035f0..ae6852cec 100644
--- a/app/models/dossier.rb
+++ b/app/models/dossier.rb
@@ -489,8 +489,7 @@ class Dossier < ApplicationRecord
     else
       avis
         .where(confidentiel: false)
-        .or(avis.where(claimant_id: instructeur.id, claimant_type: 'Instructeur'))
-        .or(avis.where(instructeur: instructeur))
+        .or(avis.where(claimant: instructeur))
         .order(created_at: :asc)
     end
   end
@@ -499,11 +498,9 @@ class Dossier < ApplicationRecord
     if expert.dossiers.include?(self)
       avis.order(created_at: :asc)
     else
-      instructeur = expert.user.instructeur.id if expert.user.instructeur
       avis
         .where(confidentiel: false)
-        .or(avis.where(claimant_id: expert.id, claimant_type: 'Expert', tmp_expert_migrated: true))
-        .or(avis.where(claimant_id: instructeur, claimant_type: 'Instructeur', tmp_expert_migrated: false))
+        .or(avis.where(claimant: expert))
         .order(created_at: :asc)
     end
   end
diff --git a/app/models/export.rb b/app/models/export.rb
index ef521e01e..be0d0816c 100644
--- a/app/models/export.rb
+++ b/app/models/export.rb
@@ -9,7 +9,7 @@
 #  updated_at :datetime         not null
 #
 class Export < ApplicationRecord
-  MAX_DUREE_CONSERVATION_EXPORT = 1.hour
+  MAX_DUREE_CONSERVATION_EXPORT = 3.hours
 
   enum format: {
     csv: 'csv',
@@ -45,6 +45,10 @@ class Export < ApplicationRecord
     file.attached?
   end
 
+  def old?
+    updated_at < 20.minutes.ago
+  end
+
   def self.find_or_create_export(format, groupe_instructeurs)
     create_with(groupe_instructeurs: groupe_instructeurs)
       .create_or_find_by(format: format, key: generate_cache_key(groupe_instructeurs))
diff --git a/app/views/instructeurs/procedures/_download_dossiers.html.haml b/app/views/instructeurs/procedures/_download_dossiers.html.haml
index 1a28d2292..87c2c7417 100644
--- a/app/views/instructeurs/procedures/_download_dossiers.html.haml
+++ b/app/views/instructeurs/procedures/_download_dossiers.html.haml
@@ -7,11 +7,12 @@
         - [[xlsx_export, :xlsx], [ods_export, :ods], [csv_export, :csv]].each do |(export, format)|
           %li
             - if export.nil?
-              - export_text = "Demander un export au format .#{format}"
-              - if format == :csv
-                - export_text = "Demander un export au format .#{format}<br/>(uniquement les dossiers, sans les champs répétables)".html_safe
-              = link_to export_text, download_export_instructeur_procedure_path(procedure, export_format: format), remote: true
+              = link_to t("#{format}_html", scope: [:instructeurs, :procedure, :export_stale]), download_export_instructeur_procedure_path(procedure, export_format: format), remote: true
             - elsif export.ready?
-              = link_to "Télécharger l'export au format .#{format}", export.file.service_url, target: "_blank", rel: "noopener"
+              = link_to t(:export_ready_html, export_time: time_ago_in_words(export.updated_at), export_format: ".#{format}", scope: [:instructeurs, :procedure]), export.file.service_url, target: "_blank", rel: "noopener"
+              - if export.old?
+                = button_to download_export_instructeur_procedure_path(procedure, export_format: format, force_export: true), class: "button small", style: "padding-right: 2px", title: t(:short, export_format: ".#{format}", scope: [:instructeurs, :procedure, :export_stale]), remote: true, method: :get, params: { export_format: format, force_export: true } do
+                  .icon.retry
             - else
               %span{ 'data-export-poll-url': download_export_instructeur_procedure_path(procedure, export_format: format, no_progress_notification: true) }
+                = t(:export_pending_html, export_time: time_ago_in_words(export.created_at), export_format: ".#{format}", scope: [:instructeurs, :procedure])
diff --git a/config/locales/views/instructeurs/fr.yml b/config/locales/views/instructeurs/fr.yml
new file mode 100644
index 000000000..3cc5fabdc
--- /dev/null
+++ b/config/locales/views/instructeurs/fr.yml
@@ -0,0 +1,10 @@
+fr:
+  instructeurs:
+    procedure:
+      export_stale:
+        short: Demander un export au format %{export_format}
+        csv_html: Demander un export au format .csv<br>(uniquement les dossiers, sans les champs répétables)
+        xlsx_html: Demander un export au format .xlsx
+        ods_html: Demander un export au format .ods
+      export_ready_html: Télécharger l’export au format %{export_format}<br>(généré il y a %{export_time})
+      export_pending_html: Un export au format %{export_format} est en train d’être généré<br>(demandé il y a %{export_time})
diff --git a/db/migrate/20210407174523_drop_unused_columns.rb b/db/migrate/20210407174523_drop_unused_columns.rb
new file mode 100644
index 000000000..244f8c952
--- /dev/null
+++ b/db/migrate/20210407174523_drop_unused_columns.rb
@@ -0,0 +1,11 @@
+class DropUnusedColumns < ActiveRecord::Migration[6.1]
+  def change
+    remove_column :avis, :instructeur_id
+    remove_column :avis, :tmp_expert_migrated
+    remove_column :etablissements, :entreprise_id
+    remove_column :procedures, :archived_at
+    remove_column :procedures, :csv_export_queued
+    remove_column :procedures, :xlsx_export_queued
+    remove_column :procedures, :ods_export_queued
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index ac440622d..73e62912b 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_04_02_163003) do
+ActiveRecord::Schema.define(version: 2021_04_07_174523) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -121,7 +121,6 @@ ActiveRecord::Schema.define(version: 2021_04_02_163003) do
     t.string "email"
     t.text "introduction"
     t.text "answer"
-    t.integer "instructeur_id"
     t.integer "dossier_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
@@ -130,11 +129,9 @@ ActiveRecord::Schema.define(version: 2021_04_02_163003) do
     t.datetime "revoked_at"
     t.bigint "experts_procedure_id"
     t.string "claimant_type"
-    t.boolean "tmp_expert_migrated", default: false
     t.index ["claimant_id"], name: "index_avis_on_claimant_id"
     t.index ["dossier_id"], name: "index_avis_on_dossier_id"
     t.index ["experts_procedure_id"], name: "index_avis_on_experts_procedure_id"
-    t.index ["instructeur_id"], name: "index_avis_on_instructeur_id"
   end
 
   create_table "bill_signatures", force: :cascade do |t|
@@ -291,7 +288,6 @@ ActiveRecord::Schema.define(version: 2021_04_02_163003) do
     t.string "localite"
     t.string "code_insee_localite"
     t.integer "dossier_id"
-    t.integer "entreprise_id"
     t.string "entreprise_siren"
     t.bigint "entreprise_capital_social"
     t.string "entreprise_numero_tva_intracommunautaire"
@@ -532,7 +528,6 @@ ActiveRecord::Schema.define(version: 2021_04_02_163003) do
     t.date "auto_archive_on"
     t.datetime "published_at"
     t.datetime "hidden_at"
-    t.datetime "archived_at"
     t.datetime "whitelisted_at"
     t.boolean "ask_birthday", default: false, null: false
     t.string "web_hook_url"
@@ -550,9 +545,6 @@ ActiveRecord::Schema.define(version: 2021_04_02_163003) do
     t.string "declarative_with_state"
     t.text "monavis_embed"
     t.text "routing_criteria_name", default: "Votre ville"
-    t.boolean "csv_export_queued"
-    t.boolean "xlsx_export_queued"
-    t.boolean "ods_export_queued"
     t.datetime "closed_at"
     t.datetime "unpublished_at"
     t.bigint "canonical_procedure_id"