I haven't seen a self-checkout in any store that weighs the bags in quite a few years in my area.

But absolutely they got machine vision looking. Once I got flagged for potential theft because I put the box to the far side of the scanning area before scanning. It flagged me as trying to steal it after I had scanned it with the scanner gun, and I got to see the video 'evidence' of my theft, including grabbing the scanner gun and starting to move toward the box.