I've noticed that performance when deleting a lot of files in flat view mode is quite poor. The issue seems to be that Opus is trying to update the view while it deletes files. It's exceptionally bad in thumbnail view and with network drives.
Switching off flat view fixes the issue and performance returns to normal.
It would be nice to have some logic that detects this situation and temporarily disables the refresh while files are being removed.
Is this on Opus 11 or 12?
Your forum profile says you're using 11 but maybe it's linked to an old licence that wasn't updated. (We can unlink the account if you want to link it to a different licence. It should update automatically if the linked licence is upgraded, but won't know if a completely separate licence also exists.)
It's Opus 12. Please update my profile.
I've un-linked it which should allow you to link it to your other licence.
Done.