It’s entirely up to you how you implement it, whatever works best for you.
If it is using a version of FMOD you are happy with and you have complete access to it then using the already integrated LowLevel may just be easier.
You could use our UE4 integration as a bit of a guide for a C++ integration.
I’m not entirely sure what you mean about FMOD Studio creating copies of sounds, the docs may have more info on this:
https://fmod.com/resources/documentation-studio?version=2.0&page=managing-assets.html