TackMax is Ttimeout, so 5 ms. That’s what I used as a basis for my calculation. TackMin is 9 ns, so that would shorten it to 40 days, without any certainty that it didn’t actually authenticate at some point at the end of it.
Incidentally, I do have another bullseye: my doNExT. I just Taginfo’ed it and it too has FF in AUTH0.