I completed SSB HV1 and HV2 last winter on Elite E-Motion rollers set to the first level of resistance (the rollers have a no resistance setting and 2 levels of increased resistance). I did not progress to a build plan as I started riding outdoors at that point. I have a power meter on my bike. I had to stand every 30 minutes or so, for 30 to 40 secs to clear the numbness. The only workout I had a problem with was the ramp test. Shifting gears and keeping balance at increasing wattages can be difficult, as can sprinting, so I don’t try to meet the power numbers on sprints, I do the best I can while staying upright. The 20 minute FTP test was not a problem.
The e-motion rollers have bumper wheels at the sides of the front roller to help keep your bike from coming off the rollers, which I hit quite frequently. The increased focus required to complete the workout on the rollers helps pass the time quickly. One benefit of training on the rollers was that my average cadence on outdoors rides increased from approximately 85 to 95 rpm. I plan on training on the Elite E-motion rollers this winter. However, I don’t think I could do the training on a no-resistance, no-motion set of rollers (which I have never ridden). I have a wall on my right side and a treadmill on my left side for support when I lose balance.