OK so it looks like hCG can be used both as a "vaccine" and as a "cure".

When I say "vaccine", I mean you can use it to prevent testicular atrophy altogether.

When I say "cure", I mean you can use it to treat testicular atrophy that has already set in.

I think we could all agree though that it's far more preferable to use hCG as a vaccine than as a cure.

I'll agree that hCG would be suitable for PCT if you had neglected to take it during cycle, but if you are prepared and educated beforehand then definitely there's only one way to go:

Take hCG from the beginning to the end of your cycle, and stop taking it before you begin PCT.