I tried it, set up one of my bikes on rollers and a Bluetooth sensor strapped to the hub/zwift on the iPad in front of me. I was going along at what I thought was quite fast around 25mph indicated, riders were coming by me like I was standing still. I’m certainly not the fastest on the road but I don’t dawdle around either. I’ve got nothing to substantiate it but felt like there was some sort of cheating going on. It may be that I didn’t have it set up properly but it put me off and I sold the rollers! I’ve tried turbo trainer as well one winter, gave that up.