Removing EXT Inputs from MAIN Mix in Overbridge? Possible?

I’m setting up a template for my A4mk2 in Ableton using Overbridge.

All is fine, apart from the signal I have from a synth going into EXT L is coming through on the Main mix in Overbridge… and I want to reserve that for the FX track.

I know you can go to Audio Routing for T1-T4 and take them out of the MAIN (so you just record them as individual tracks), but, the EXT synth routes to the MAIN regardless and there seems to be no setting.
I have got the EXT in coming in ‘clean’ to it’s own track, which is all I need, but want to stop it hitting and dominating the FX signals that I’m using MAIN for.

Any ideas?

Not that I’m aware of. I had this exact issue with my DN and it’s the reason i got my M2. The good news is you can get a cheap interface and use Overbridge along side it.