[Loliceman]

Thanks for the detail.

I think I have it but first I'm going to code a bit more simply and try to code enhanced bluetooth streaming. Am I correct that there is no reason to backup the existing FSC certs prior to patching? or are there files I should copy via FTP before patching that I could reinstall for some reason???

In my opinion - You don't really need to. If you ever need the "original" fscs and certs for your vin, just ask someone here on the forums nicely for a repair pack and you might get it.
Coding bluetooth streaming can also be done by VO option coding, then fine-tune with settings and parameters for your preferences.
Good luck!