HP tuner for multiple vehicles ?

I am in the market to get a tune for my 2015 Ford Edge Sport, but I know once I do this I will likely want to start tuning other vehicles I have as well. While I will probably fiddle with some of the basic settings, I will likely be asking professional tuners for the engine work. My question is if I have my own HP tuners and credits, can I purchase and use tunes from tuner vendors without them having to buy credits on my behalf? I would be tuning both Ford and GM, of which it appears I would need 2 credits for each vehicle. Just looking for what exactly it would take to use my own HP tuners as a main hardware and software device to facilitate purchasing 3rd party tunes for all of the following?

2015 Ford Edge Sport 2.7
2014 GMC Sierra 5.3
2011 Cadillac CTS-V 6.2
2004 Cadillac CTS-V 5.7

Thanks,

assuming they use the file you read from the vehicle you shouldn't need to relicense anything sent to you. However you would need a license for any file you want to flash to your vehicle using your interface.