It seems like one could implement something similar to the Peachy concept with basically a laser cutter(of which there are several open source designs out there) over a build vat plus a pump hack or a stepper controlled submersion setup for z control, using the saltwater concept. Since the laser would be mounted perpendicular to the resin you wouldn't have the angular issues to deal with, though the top speed and scale of the printer would probably be less than the Peachy design would be capable of. Probably would want to isolate the laser gantry from the build vat too.