I don’t have my AR or a 2nd Elecktron device to compare with just yet, but what happens if you slave your 2nd Elektron device with a midi cable from the first (master) which is slaving to Ableton over USB. I’ve been syncing an LXR drum machine in this manner to record Audio into Ableton with and seems to work just fine for me. I’m using an offbeat audio interface, the Phonic Firefly 808 Universal on a 2006 MacPro. That way you just have to adjust the midi delay setting once in Ableton. Just a thought.