I’ve commented on this before but I think the ramp test really depends on the type of rider you are. I’ve come from the background of doing 30 min as hard as I can solo on the trainer (Friel method) to come up with ftp. Its grueling sure but its just what I consider my norm.
I’ve spent years being a triathlete before becoming a roadie the past year or so, so my short term power isn’t great. I find that the results I come up with the ramp test are not inline what my 30 min test. The first time I tried it I had not done high intensity above ftp, so to then hold wattage going above it one minute at a time my body wasn’t ready for it.
Results from the ramp showed me my FTP was 308. Couple weeks later I did my 30 minute all out on the trainer test and came up with 347.