There is not, unfortunately. There have been lots of requests for audio improvements, and that's one of them. The devs know already, but they also see the mess that OBS's audio has become over the years of tacking things on here and there, and want to wipe and redo it instead. As a software guy myself, that has seen the result of an originally good design under a big pile of band-aids, and as a live sound engineer on the side, I fully support a rewrite at this point. It's already unmaintainable, and it demonstrates several reasons why pro gear is the way it is.
They're still figuring out just what they want to do and how it should work. While they do that, I expect what's there now to stay as it is, with no more changes/additions/fixes/etc., and at some point there'll be a version that completely changes everything to do with audio. Then the answer to your question might be, "Yes, it's easy! Here's how..."
But until then, keep using the separate audio loopback.
