The plan is for the 1/4" output to mirror the XLR output, and it will also be defeatable by a toggle switch on the face of the pedal (we carved out a space for it already, you can see the empty spot there). So you can have cabsim on XLR and 1/4" at the same time or you can run without cabsim.
"But what if I want cabsim on one output but not the other?" Sorry, this is the cleanest way I could find to do it. Letting you mix and match output signals adds additional complication to an already complicated (at a circuit level at least) preamp.
We are at the sim, it's been fully planned and spec'd out, it just hasn't been implemented yet on this prototype. I've been taking things step at a time to make sure Tony and I stay on the same page with the design, so rather than put everything in at once and audition a finished unit I've been making sure he likes each stage before we move on to the next stage. I think this is the 5th or 6th prototype, and we're finally at a sound we're both really excited about. Adding in the cabsim is the last step, then it will be ready for its official announcement at the NAMM show, and depending on how quickly the cabsim falls into place I hope to have things set up by then to put it into full production and make it available for sale.