Yes, but you control the trainer and enable ERG from >>outside<< of Zwift with the Wahoo Fitness app on your phone or your ELEMNT head unit.
Simply disconnect the KICKR as the Controllable Trainer from the Pairing screen in Zwift, then use your Phone or ELEMNT to do the trainer controlling (ERG or otherwise). The power source within Zwift stays the same as what you’re using already.