Don’t overthink it. Set it to ERG mode, spin up to your target cadence as the warning beeps start and focus on holding the cadence. Even though you probably don’t hit the target watts until a few seconds into the interval, you’ll also not hit the rest value for a few seconds at the back end. So, you’re still stressing your max aerobic capacity with each interval, and moreso in the later ones of the set.
If you do any of these workouts outdoors, you’ll see that the wattage range is often +/- 10W. So, it’s not like being off by that much is going to stress the wrong system.
No, if you want a visual smoothing e.g. over 3 seconds, you have to set that in the settings of the TR app.
The smoothing done by the Kickr completely ignores the actual watts and just sends the target watts for the app to display. It basically lies to you. That power graph is impossibly smooth. No human can achieve that.
just zoomed in on my intervals today and it looks just like that (green line steeper), so I guess I’m good? But yea same deal today where the power reading took about 6 seconds to hit the target, no matter what my cadence was.