Can the dialog shown during app install/upgrade be controlled programmatically?

When installing an app in Confluence, the following dialog pops up during the install…

app-install

However, the dialog seems to disappear once the app is installed, even though the app has defined a migration task (by implementing ActiveObjectsUpgradeTask) and is still busy doing Active Objects migration behind the scenes.

Is there a way to programmatically control that dialog, or pop up my own custom dialog while the migration is taking place, so the user can be informed that the migration is still active, has finished, etc?