Glad you made it through. Sometimes when I do a sweetspot workout I experiment with cadences e.g. one at 90 rpm, one at 85 and one at 80. Around 85 works best for me. I do do some specific workouts with some intervals around 60 rpm but don’t go more than a few minutes this slow.
Ramp test at 53 rpm. Ouch!! I would need to be standing to go this slow at high resistance levels.
I think you’re going to find sweetspot workouts like Eclipse challenging at low cadences. If you are going to do them at less than the workout instructions recommend for cadence you might want to drop the intensity say 5% especially if you’re doing sweetspot base as this has multiple days all at sweetspot. Your muscles will take a hammering if you do them all slow. Even though I’m a roadie I’ve got a MTB and find you need a broad cadence range say from 50 to 110 so it would pay to train at various cadences.