Either of those tests are likely to, meaning Sweetspot ends up being threshold work.
But.....I'd wager that going into 3 x 20mins untrained is probably more of the issue?!
tbf I think doing the Ramp in TR for then doing TR workouts makes sense. How useful the number it gives you for outside riding I don't know, but have never used it.
@dbr i'll let you know tomorrow!