I used to use Training Peaks 20 years ago as a desktop application. One of my favourite features was the ability to plot a specific Critical Power (say 20 min power) vs date. I liked this because unlike a power curve which just shows my best power for a particular duration - seeing the CP20 for my last 6 months or whatever range allowed me to see where that effort fit in with other similar efforts if it wasn’t a PB. Also it allowed me to see how much better a new PB was than previous efforts.
I am relatively new to Intervals.icu so not sure if this is already possible but if not I think it would be a great new feature.