Say you are doing a 90 second interval at 120% and you fail at 45 seconds and stop pedaling. Is there a way, without switching to standard or resistance mode, to make the software reduce the watts to say 40% so you can just spin lightly and prepare for the next interval? Seems the software should recognize that you are at 0 cadence and lay off the resistance.
Sadly there is not a way to do this 
. ERG mode follows the commands of the TrainerRoad Target Power at all times.
One option would be to pause the workout and skip ahead to the closest recovery valley to allow you to lay off the resistance. You could then rewind back to your previous spot if you want to resume your unfinished interval. That being said, swithing to resistance mode woulc be your best option when unable to complete an interval becasue it gives you complete and total control of your efforts.
Sorry I don’t have a better solution for you at this time.
Sounds like a feature request. Hot key to drop power target to recovery rate for remainder of interval.
Could you add it to the growing list of feature requests?
I’ve tagged this thread with the #featurerequest tag 
Thanks Bryce!