As far as I am aware, overbridge individual track outputs are “Stereo mono” as in the left and right channel are duplicated with no stereo imaging applied to them, so you really only need 10 channels;
L + R Master for effects
1 - 8 for individual tracks
I don’t have VCV pro, but did dick about with VCV1 prior to getting any hardware. HostXL allows you to host a plugin within VCV does it not? Maybe you could track out L + R master, T1 - T6. You’d lose two channels unfortunately. I don’t think you can run two instances of overbridge at the same time.
If you can host VCV in a daw, you’d probably want to do that. Use OB in the daw, take the channels and route them to the VCV plugin, use VCV Library - VCV Audio 16 to then receive the audio channels via that into your rack. I’ll dick about tonight if I have time and see if there’s a way to do it without a DAW but I don’t have pro so will be missing some of the tools you have on offer.