Hi @woodslanding, welcome to the GP familly 
First if all Hollyhock is not GP and it would probably be a mistake to try to transpose exactly what you have done with Hollyhock to GP. You won’t have another option than going deep into GP to see how it could fulfill your needs and for sure there is a way it will.
Some users use GP a bit like you with a single Rackspace, perhaps it could be a source of inspiration for you.
The only Rackspace I made, which could come close to your needs is the following one, in which plugin presets cannot be changed, but this could be feasible with an additional GPScript.