Hey,
well, the reason for the "compiler" restrictions mentioned in the docs, is that the SDK is shipped with code example projects and precompiled static libraries for these targets. But the SDK also comes with its full source (the 'includes'), so nothing is really preventing you from using another IDE/compiler. The VS 2019 projects should also be relatively safe to upgrade to 2022. With XCode things are more complicated, and I would there recommend creating your own project from scratch instead of updating the existing one.
In the bigger picture, we probably should update the Cineware SDK to also using CMake as the Cinema 4D SDK does these days, and with that offer more flexibility. I have this on my bucket list, but it is not very high in priority, because the Cineware SDK is our least requested SDK. When you have concrete problems with creating a build system for the Cineware SDK for your desired compiler (and IDE), just post the questions here, and I will try to help you.
Cheers,
Ferdinand
