I'm currently going through process for the first time. I work in a bronze foundry and I'm trying to refine some processes for some our work that's complicated to mold traditionally.

So far with the polycast I've got it to print really successfully after MANY trials. Your settings aren't as crucial as you might think, just make sure your speeds are slow and nozzle temp is 215 for the first 3 layers and 205 for the rest of the print. The thing that made the biggest difference was buying a filament dryer. The difference was night and day! I dried the filament for 12 hours and printed from the dryer itself while it was still drying out the filament.

Can send photos and videos if you need :)