I wish I could provide some kind of timeline. When we work to make new trainers, sensors, or treadmills available in Zwift, a good amount of that effort includes working with the manufacturer, and some manufacturers may not want their products made compatible.
You may receive a clearer answer by asking Bkool if they plan on supporting Zwift compatibility for the Smart Bike in the future.
While Zpower may not provide spot-on accuracy, the speed and cadence sensors involved aren’t a heavy investment - the only thing you’ll likely need to worry about is ensuring the sensors can mount properly on your frame. For better accuracy, a power meter could be added to the mix as well.