So as I was playing with aligning and rescaling layers with the transform tool I noticed that what you see while in "transform mode" (semi-transparent) is by a couple of pixels off to the result you get when you accept transform.
Am I missing something or is it a bug? Hope you don't mind another post by me today, but I thought I'll ask before considering it a bug (2.9.9 - git 3a86ede).

That's because it's a preview: https://userbase.kde.org/Krita/Manual/F ... alising.3F

hmmm... any suggestions howto cope with that? I do not mind a tad "blurry" preview, but to make proper alignment I need to be able to get the preview shape and final shape in the same spot.

Well, the move-tool doesn't use any preview, hence why it's so slow.