How is the latency for you? I know blackhole is advertised as 0ms itself, but I always found that crossing virtual devices incurred the input/output latency of the daw itself.
I haven't experimented with lowering these numbers in maybe two years, but I use BlackHole to route 8 channels from Traktor to Ableton Live (all four decks in stereo as external outputs). I have one big aggregate device with my internal speakers for clock, the BlackHole bridge, and an original RME Babyface for the physical output.
Looks like I have Traktor set to 192 samples @ 44khz. It's showing "4.4 ms processing + 17.6ms output = 22.0 ms" in its UI.
Ableton is set to 128 samples, and showing "Input Latency 4.72 ms, Output Latency 6.05 ms, Overall Latency 10.8 ms".
So maybe 33.8 ms in the whole pipeline? Although I throw audio signal across the room via the Babyface's optical out to a cheap optical -> RCA box, so that's probably adding a little more to my physical environment.
I've had this same Traktor/Live setup going for a long, long time. At one point I even used a physical loopback with the Babyface's optical out/in carrying 8 channels between Traktor and Ableton. That was sadly better than any software available before BlackHole. It was solid, although a bit higher latency, and it's nice to be able to use the optical out for its intended purpose!
I used to get very occasional crackle this BlackHole setup, until I tried a random tip of using the built-in speakers as the clock source on an aggregate device. It's been rock solid since. I could probably lower sample buffers even further these days (M3 Max)...
