I can also confirm Mojave does not work well with Cinema4D R18, its laggy when moving around viewport. This is on a 2013 Mac Pro. On my older 2009 Mac Pro with High Sierra Cinema4D R18 doesn't have these laggy issues. Darn it I shouldn't have updated, hard to know until you try it though. I wanted dark mode, but dark mode doesn't even work in open / save windows! This could be another reason to move over to PC land?