Yeah, I did a ton of research and this is a tough on to answer. It seems the only way to gain this knowledge is to do it on your own. I think I am going to give one more dose of bloom nutes, then flush. By how fast this one has matured, I think It's reasonable I will be cutting on day 70.
If you get a straight answer, I'll be impressed. There seems to be a thousand different workable answers, but none are "right".
Best guess seems to be the best answer I ever got.