@woo49, that’s a tough nut to crack, right? I had to do a few “fact-finding” sessions in order to get myself into the 20-second ballpark. But once I found the pretty reliably repeatable wattage, Erg mode actually worked surprisingly well. In fact, I think it kept me as accountable as a real-life coach standing in front of the bike yelling in my face (coupled with some really well-timed songs, of course).
As always, a bit of trial and error is useful, and when it comes to all-out efforts, it’s vital. Seems like pacing wouldn’t be that big of a concern with such short efforts, but it’s just as important as any duration of effort if you’re truly looking to understand your current limits.