H4ndy

While OBS will run virtualized, you will get a massive performance hit if no GPU is available and everything is done in software rendering. And GPU-enabled cloud servers are quite expensive.

Your device must support one of the common audio protocols to work in OBS (for Windows WASAPI for example). There's also an ASIO plugin available.

OBS will probably not add any specific code to support non-conforming device(s) without an external maintainer willing to keep the needed code updated over the years.

Some kind of plugin manager/installer is certainly something that will get added to OBS, probably sooner than later.

The AMD AMF encoder is still preset in OBS, it just requires somewhat recent GPU drivers to work (19.7.1 minimum, 19.9.2 or newer recommended)

The OBS team has a very friendly relationship with XSplit folks, they're nice people and strive for a better product for all users.

NVENC is not supported on macOS because Apple does not expose it in their VT toolkit that OBS is required to use to access hardware encoders.