It would be really awesome to have some kind of adjustable trainer “speed” setting in TrainerRoad.
Maybe this could be automatic based on TR’s own testing for certain trainer models, or maybe it’s a customizable advanced setting in the app. The setting would allow you to customize both the interval start and interval end timing, in seconds. So if you knew your trainer was slow at ramping up power (which becomes painfully evident on things like 15-second repeats), you could set TR to -5 seconds for interval starts, and maybe 0 seconds at interval ends. This would allow the resistance to begin ramping up 5 seconds before an interval technically starts, but still end on time.
Other ideas… maybe this setting is only applied to intervals that are under 1 minute in length (or maybe all, for consistency); maybe there is a specific short test “workout” that you could do on the TR app that is specifically designed to measure trainer lag (like a short 10 interval set of 30% to 90% intervals of only 15-seconds each), and the app would calibrate itself against the results, or give you the number you should set (much like a ramp test).