Any way to add a cadence range when creating a workout?

In ERG mode, it seems that 85-90 RPM is what it takes to stay at the programmed wattage.  I notice if i try to increase my cadence, the resistance drops significantly to bring my watts down to what I set it at.  I think it would be great if you could select a cadence range for the wattage you choose.  

Using kickr, in zwift workout mode I can set the duration of the interval to lets say 5 minutes, then drag the cadence icon over it and set to 90 rpm. This will give me a range of 85-95 before it tells me to spin faster or slower. ERG will adjust the intensity automatically.

Brilliant!! Thank you!! I set up one of my workouts to 95 rpm. I’ll see how it goes tomorrow.