I can see 1024 on mixing, but that is way too much. I have always used 256-512. At 512, I thought I was using too much.
I am not really doing a 'mix' per se, but playing back tracks that will be used for playback while recording. I have to have the lower latency. These RME units can get real low. I had zero issues with 8.5 and latency. The major differences I see are VST3 and X3. I hope, I can get around the differences.