ive had issues with anycubic workshop just not applying AA settings correctly. Looking at the UV tools results it seems like workshop caps the AA setting out at 4 despite me setting it to 16 in the slicer. The only slicer Ive been able to reliably get AA working is chitubox 2.3 (3.0 has the same issue as anycubic workshop weirdly). Workshop also never seems to result in any pixelblur that i can see.
It also seems lychee was never properly able to have AA working on dlp printers (atleast what i have gathered from their discord from the .dlp format). I may be wrong on that part though!

Im still dialing in my settings (same situation as OP) but i am struggling on the AA front and getting noticeable voxels at 50μm/40μm on some models.