The good thing about your 3-min, 6-min, and 12-min results is that you can put those (non-sprint) numbers into a critical power calculator like the one on HighNorth’s website:
and get CP/FTP and W’
Or you can use something like GoldenCheetah, I’ve been using the latest beta (v3.6). Those are all free tools, on the paid side I prefer WKO5 to handle estimates.
For some reason my estimated FTP (WKO, my own testing) ends up being closer to Critical Power than the above screenshot. For example 273 Garmin eFTP vs 273 WKO5 mFTP vs 275W GoldenCheetah Critical Power. Only 2W difference between GoldenCheetah’s extended CP model and Garmin/WKO5.