Unlike B/W films E6 and C41 have the same times regardless of film type. I mix T64, Provia, EPR and EPN all the time when developing E6.
I use the Arista kit and never process one-shot. I just reuse the chemicals for about 30-36 sheets of 4x5 or 10-15 rolls of 120. Keep in mind if you are not using these one-shot that you need to extend the 1st developer time by a percentage for each roll. Check the instructions but they are usually around 4-6%.
Never used them in a processor before, I develop in a Mod54 and reels and tanks.