Migrate Rollback puts entities into trash

I agree that rolling back a migration should delete the entities instead of trashing them. If Migrate has an API for hooking into the rollback process (before it starts), we need to set the ignore trash context like we do for similar use-cases, e.g. \Drupal\trash\EventSubscriber\TrashIgnoreSubscriber::onDefaultContentPreImport().

Thanks for the feedback Andrei, I'll have a closer look tomorrow. Meanwhile, I thought about one more case - if the item is removed from the migration source and migration import is being run with --sync flag that should also purge the item directly. Thoughts?

ref:

 --sync                                Sync source and destination. Delete destination records that do not exist in the source.                            

That one sounds like it should be configurable.. I don't think either trashing or deleting the entities on the destination is the correct answer in all situations.

Can we add custom flags to the migration process/command? Like --trash=true|false?