Try this. I’m in the same boat. Ramp test overestimates my FTP, and as a result, the TR workouts are all a little too hard. SS becomes threshold, and Threshold pushes me to VO2max. 1-2 min VO2 max intervals are doable, but the 3 min intervals are brutal.
Also check out this post about the approach recommended by Steve Neal - basically advocates for putting a cap on workout intensity based on HR. I think there’s merit to this for older athletes.