Another noob here

Trying to understand the licensing/credit system for my needs.

I have a 2.2 Ecotec installed in a 1978 Toyota Celica used for endurance road racing (24 hours of LeMons) it runs fine with a flashed PCM I brought with a standalone harness.

But of course I want to get a little more power, I have added a header and a 3 inch exhaust and have some future upgrades in mind.
Not wanting to screw up what I already have I brought a couple of used PCMs to experiment with, I'm thinking start by doing my own standalone mode and then play with tuning.
Ideally I would like to have a backup unit ready to swap in in case of failure and maybe the ability to swap a fuel efficient vs performance PCM depending on how a race is unfolding.

So my question is how do I license my system to tune multiple PCMs for this engine?
It's a 120k miles junkyard engine so will eventually (maybe next race) need replacing does swapping an engine have any impact on the licensing or is it PCM specific?

I also have a Saab 2.0 Ecotec B207L complete engine that may find it's way into the Celica in the future, can I tune the Saab Ecotec with HP Tuners or would I be better to run it with the 2.2 Chevy PCM retuned for the turbo.

Cheers
Brett