It literally shows up as an audio device in Windows sound settings, and "just works" - what prompted you to reach for documentation?
Unless you tried one of their more advanced offerings, like Voicemeeter - which also looks pretty intuitive judging from the screenshots. (Never tried it, on Linux I get this capability via JACK.)
Ah, I see you're a man of culture as well :) I've seen exactly what you're talking about, and yes - once a DAW is in the mix you have to account for the DAW's routing.
Historically, audio routing is something you do within a DAW, between tracks and plugins and the like - and routing sound between separate apps is a niche OS feature based on hacks and workarounds (like VAC) instead of the OS providing primitives that map to the concept model. In an outboard setup you could at least trace the cables to see what's connected to what... and that's what audio routing on any OS lacks (JACK patchbays notwithstanding, since JACK is a pain to run alongside normal PulseAudio).
If I remember correctly, it was non-obvious how to set up monitoring with Live and VAC, so I ended up using ASIO4ALL which can bridge multiple soundcards - but prevents other programs besides your DAW from using them. You're right, audio routing on Windows is a bit of a mess, MacOS is plug and play with strings attached, and on Linux there's JACK which has potential for greatness but is somewhat underdeveloped. Same as any desktop feature on these OSes :)
