Yes, TR sends the resistance change instruction 2 seconds before the start (and end) of an interval. It’s done to compensate for the inherent delay in most smart trainers, and hopes to align the power output more closely with each h interval block.
It can catch people off guard if they have a fast changing smart trainer (Kickr or Neo are good examples) and you need to be ready to apply power a bit early, but usually isn’t the cause of issues like you describe.
Currently, the best way to handle a Clinch or time when you have slowed your cadence too much in ERG:
Stop pedaling (if not stopped already from a Clinch).
Back pedal for about 5 seconds. (This signals to the app to release the resistance unit).
Resume pedaling with a quick and forceful effort. The resistance will be low, but there is a very small “bump” of resistance that you must overcome to get to a higher cadence like 90 rpm.
Continue pedaling with the desired cadence (resistance will be low and easy) and the app will raise the resistance to meet the current power target.
Finish the interval and workout as normal.
You mention an issue in a recovery interval. Are you having issues with the trainer not dropping resistance low enough in those easier efforts? If so, that can be a problem with some trainers if their resistance floor is too high. Which trainer do you have?