Workout mode perceived effort

When using Trainerroad to drive my KICKR on Zwift island I noticed an interesting phenomenon: My perceived effort in an erg-mode interval decreases when climbing and increases when descending.

I think it would be very interesting to experiment with this in a workout mode to see if it can be used to motivate a rider to complete a harder interval. For example, simulate a hill at the end of a VO2Max interval to help the rider finish strong.

I wonder whether some of the riders reporting reverse resistance changes on the KICKR (i.e., easier when going up, harder when going down) may actually be experiencing this effect.