Some of the Zwift workouts have specific cadence profiles. The onscreen prompt tells you of the cadence, but that’s the last you’ll see it in that workout segment. Take a lesson from the TrainerRoad approach and have an onscreen prompt that real-time tells you to increase or decrease to get in the range of the desired RPMs.
All workouts I have done that have a cadence target have told me when to pedal faster/slower across the upper middle of the screen. The threshold is about 5 rpm either side of target.
I recently did the Gravel Grinder - Cadence Pyramid and didn’t get that onscreen - unless my RPM is so perfect that I never get outside of 5 rpm off target! And since I know that’s not my skill, I’m not sure why I don’t see anything.
I just had a look at that workout, very strange that its strange that you dont get it, and that Plan is one of the more recent ones so would expect it.(some old workouts dont have cadence targets hence no warnings).
I might see if I can fudge the plan to get to that workout and try myself.