You are spot on with both accounts. Large flat surfaces areas are harder to get off the plate, and those large flat surfaces lead to uneven cooling in ABS. The slots allow not only the part to come off easier, it allows for uniform cooling to prevent warping.
Depending on when you bought your TAZ 6, it will be made on different printers. Throughout its lifetime, the TAZ 6 parts have been printed with Mini 1’s, Mini 2’s, TAZ 5’s, and TAZ 6’s. After we generate a gcode for a particular printer, we will run that on various printers and send it through Strength and Cosmetic testing. Once it passes pull out, torque out, drop tests, cosmetic tests, etc it will be approved for production in our cluster.
Is there some reason you don’t use PETG? I’m asking because I have used it as a replacement for ABS, PRUSA now prints all their printer parts with PETG and it doesn’t stink like ABS; it’s almost odorless.