Just observing again that trainerroad appears to have some anti-death spiral logic in it. I was having trouble keeping up the other day and it definitely softens up the control if you aren't within about 10%. They must have some kind of death spiral detection. They definitely have some annoying PID behavior left over, I particularly am annoyed at having to push pretty hard after an interval is over if I didn't quite keep up at the end. I usually let it pause the workout. They clear out the integrator term so it's not as difficult to start up