Do you really mean after a gen1 collection?
Yes. By that time the tuple was probably around for a while. Also, the chances that it will be mutated will be smaller.
I won't bother arguing <wink>, but then why not at the start of a gen1 collection? Nothing that transpires within a gen1 collection is going to change a given tuple's trackable-vs-untrackable nature, and if untrackable tuples are indeed much more likely, there seems nothing to gain (but something to lose) by making gen1 scan untrackable tuples multiple times.