I have also been trying to find good resins for the MoonrayS. The formlabs resins are too thick, which doesn’t work well with the Moonray’s high tilt velocity. I’ve had pretty decent success with the eSun brand from Amazon. They don’t have any of the engineering formulations, but a good selection of colors, and the lowest prices I’ve found.
Power Resins brand Cast is the only castable resin I’ve found so far that gets good prints, but the burnouts have been very ashy.
I’ve been recommended B9 resins and Envisiontec’s EC3000 for casting, but I haven’t tried them yet.
I’ve also been looking at 3Dresyns. They have a huge selection of all sorts of resins, plus additives to tailor a resin to a printer’s specs. This seems like a good fit for MoonrayS, which doesn’t give a ton of control over exposure, velocity, pause time, etc.
Let me know if you’ve had some successes or failures, or have come across new info.