If you can use backpedals instead of lowering intensity that is preferred, expecially in SS workouts. Try that as a strategy instead. Maybe as a reward or carrot for longer intervals. For instance, in a 20 min SS workout I allow myself 3 backpedals should I need them (1 every 5 mins). If I don’t use it, I’m allowed to carry it further into the interval. It gives me outs should I need it. Most times I don’t, but it’s comforting knowing it’s there which makes me push through the intervals.
Also the backpedals allows me to break the work in manageable chunks. Four 5 minute intervals is doable where one 20 min interval is mentally daunting.