Using only the TF – is there a way to have the the dry signal NOT running through the a/d-d/a and existing as if in relay bypass? I guess sort of a "Kill Dry" mode but still hearing the original signal mixed in.
You could do that by using a mixer. Connect the TF in the mixer's effects send/return and set to Killdry ON. Connect the guitar to one of the mixer's inputs and then you can mix the dry guitar with the 100% wet signal from the TF.