Hello,
As someone who works at Formlabs I can answer your question. We've had some users have success with printing castable and pressable parts on the Form 2 and, to be honest, we've had some users with less them optimal results. We are very aware of the current issues people are seeing and I can honestly say we are working on a solution that will fix the issue. The good thing is it's a resin issue not a hardware or printer problem. I would say more but I have to leave it at that, sorry it's not a direct "Yes, do it" or "No, don't do it".
To answer your units per liter of resin question:
3 unit bridge, with supports - 2.04 ml of resin to print - you can print 490 of these parts with one liter of resin and it would cost about 61 cents per pattern
Full contour single, molar, with supports - 1.41 ml of resin to print - you can print 709 of these parts with one liter of resin and it would cost about 42 cents per pattern
I just did a full Form 2 build plate with 50/50 single full contour molar and 3 unit bridges and I fit 38 total parts and it will take 5 h 15 mins to print
You can always download our nesting software for free, import your STL files and see how much material the print will take and see print times.
https://formlabs.com/tools/preform/ I hope this helps and will add updates when they arise.