Ah, yes, I strongly recommend to not mirror pixel components. Two reasons. You may want to be able to change its shape (asymmetrically) later, and then all components should be oriented the same way. Then, you may run into overlap/knockout issues due to path direction problems.
What may be a good addition is that if you flip components whose names start with _pixel or pixel, they are flipped back to their original orientation after they are mirrored (in groups).
EDIT: Made new post with the ‘not directly over cursor’ thing mentioned here.
There were some situations where the Pixel tool deleted pixels not directly over the cursor, but in the new beta can’t reproduce, will create a new post if I notice anything, but from a quick test it’'s working