Have been trying this recently.
Using OB for multichannel input into Ableton’s per track EQ, routing, live mastering chain, and macro FX is primo. Even stock Ableton FX are miles ahead of Elektron’s in terms of quality and depth. Plus you can bus things and get real sidechain compression etc.
However OB’s sync on M1 devices is pretty broken at the moment, so even adding some basic stems or loops in Ableton clips doesn’t tend to sync well. So yeah, no sync mode is the way to go, using Ableton purely as a mixer.
Would be ironic if i’d have to pick up a 1010 blackbox just to get some extra loops and stems into my liveset 
It’s either a 500€ blackbox with tight midi sync, or a 500€ ERM multiclock plus interface with an extra output to use for the audio rate sync. Ugh.
@eira.hx figured out a cool method for hybrid liveset sync here: Possible hack to work around latency issues in Overbridge