It would be interesting to try set wattages with the kickr but TBH I’ve never felt a want or need to do so. I’ve done a lot of kickr Upupup workouts and never set anything. I have an interval trainer app for my phone that I set the rest periods to display what I’m doing for the next effort - gearing, revs, etc. No real thinking as such as it’s right there in front of me telling me what to do.
If you want a good strength session, set the resistance to 100% and do an effort
I do those from time to time and work on doing 12 pedal strokes, or 6 revs in 53/12.....brutal!