This is an issue for me with PDMS as well, and the reason I have not switched to FEP, as it won’t get better with that system. I’ve tried to get Peopoly to confer on the issue and I don’t get any clear response. I can print either posts in the corners or post in the middle, not both. The problem is this- the prints around the edge contact the film/PDMS and push down the surface slightly, and that translates to a bow in the middle of the build plate, increasing the initial layer thickness in the middle causing a fail. .0005" is enough, and that’s not a lot of distance to warp. The new acrylic plate for the FEP is a step to fix the issue, but I am leery to invest more in Moai printers without some solid back and forth on how to deal with this problem.