Potentially, if you took a feed to the TAC insert card pins from the right point in your CAPI module. Using the TAC insert balancing / debalancing cards would help. Might depend how the fader is implemented. Maybe drop Jeff at CAPI a line and see what he think?
Side-note: those TAC racks are great, and Cemal is super helpful. I use the insert return pins on one rack as a separate line-in for a bunch of Helios clones I built, he helped me sort out what I needed there.