The AT equivalent of 50 is a 68, according to that latest PDF (Management of a Diabetic Cat using Long-Lasting Insulin) in the TR protocol sticky. I think 64 is probably close enough that if you want to go with the 3 times under 50/68 you could certainly do that. If you go that direction, though, when the 3rd time happens you need to take the full reduction of 0.25u.
Your other option is to shave doses with each time below 68 - but don't mix these two strategies.
Our school gets out 6/13 - i'm ready! the kids are so wound up and all of the adults are just as ready for school to get out. I'm ready for the 5th graders to go to middle school! :lol: