Depending on what you're using, you could use Erase on-cycle. If you're using a dry compound that doesn't aromatize, then you don't need to use it on-cycle. If you're using a compound that does not have AI properties, then you could add it in during your cycle.
Using an AI during PCT is not always the best idea - you'd be better off using something like Invalid Link Removed, that controls estrogen, but doesn't kill it. You're going to get much stronger of an estrogen rebound if you use an AI during PCT.
In the end, what you use on-cycle and in PCT is ultimately up to you.
~Rosie~
The Primordial Performance