They do take exactly at best 10s, 1 GCD happens at 0s, 1 at 2.5s, 1 at 5s, 1 at 7.5 and 1 at 10s. A little faster if you're the fastest machinist in the west.

As much I'd certainly appreciate some intricacies like you propose, if they ever do something about FT, I wouldnt expect much more than raw potency increases...