Soundflower, Jack, Blackhole, now this...

[cuttime]

Haven't had an opportunity to take it for a spin, yet:

https://www.vb-audio.com/Cable/index.htm

[MIDI Life Crisis]

Looks kind of useless, frankly, and the video doesn't exactly instill confidence. lol That's an awful lot of hoops to jump thru for such a limited return from essentially an unknown company. The fact that they are giving it away speaks volumes...

[CharlzS]

Kind of the equivalent of Soundflower functionality for Windows. Looks like their entry into the Mac environment. Their other product, Voicemeter (in all its incarnations), is widely installed and used in the PC community to access/consolidate multiple audio sources for podcasting, webinars, etc.

[bayswater]

The fact that they are giving it away speaks volumes...

The other three; SF, Jack and BH are also free. SF didn't survive Catalina but still works fine for me on Mojave. Jack was a port from Linux to use with Mixbus but isn't needed any more, so there's no reason for anyone to update it for OS X. Another alternative is can only be a good thing.