Well.. i have not been around for along time, but i keep checking how thigs are going on at lab from time to time (because of my own intrest).
One big thing turned out to be 3shape Cambridge and how it make slices (slices are essentially layers in print job). Slicing cambridge produces is sometimes "complete and utter bull****". Its improved a bit over time, but not enough. And slicing issue does not always "go away" even if you alter the created object a bit in 3shape dental system.
Solution was to get 3rd party program: old and free version of Netfab which allowed manually making adjustments to .stl files. Also some cases we had to use Rhino. New version of Netfab is crap and does not have some features that old one has. Bego is adjusting their VarseoSplint material and new one should be out in october 2017.
So some issues were due that slicing and partially also because of post processing, even though flashing unit that was used was accordance to specs specified in material manual. Unit that we used had tendency to heat up too much and that made end product fragile (we had experienced some breaking when in use). Solution was to make post processing in multiple parts, flash things for few mins then wait and again.. but that was pain in the ass. Now that lab has new flashing unit (BEGOs one with protective gas),things work a bit better. Also models are now coming up nicely, even hollowed and horseshoe shaped, full models.. which we had some troubles before.
Overall, when slicing is ALWAYS verified and fixed using 3rd party apps (with knowledge on those things) then the quality and consisteny of the printer is good. For us, the post processing is simple and easy enough even for reqular (not digi-native) lab tech to handle. Biggest issue is Cambridge, because slicing it produces simply are not consistent enough.
If you dont have much understanding in 3d modelling/slicing, then i suggest that find someone from your area and ask for help! that is how few got things sorted. Luckily we have an Univ. of Applied Sciences, which is doing research on different 3d printing possibilities (resin based and also metal printing),they have given us good tips, esp. how to deal with that ****ty slicing by cambridge.