Last year I tried this driver (and Soundflower, and a bunch of other similar stuff) because I needed to transmit my system audio + microphone via Skype (online music classes thanks to COVID). I couldn't get it to work properly for my setup, where I wanted to listen just the system audio through my headphones but route system + microphone to Skype. I ended up buying Loopback [1], it's not cheap but it worked pretty well, it's pretty easy to use and enabled basically any kind of connection I wanted. I leave it here because it took me quite some time to find alternatives, so if anyone finds this driver doesn't cover their use cases maybe this other is helpful.
Literally tried using BlackHole with the same aim you do, but couldn't believe I was unable to route an input (BlackHole) to an output (DisplayPort, for example, in my case).
After hunting agressively on Google I was stoked when I found Apple's native, in-house solution: AU Lab.
I've also seen Source-Nexus, that has plugins for Pro Tools as well as VST/AU, and you can make multiple named drivers. It would work pretty well with Loopback it seems.
https://rogueamoeba.com/loopback