I know it sounds kind of freak, but let me explain:
I am about to change my casette. I was thinking about a closer ratio than my 36-11, because 80% of my Zwift training is either on ETP mode, fast routes or moderate climbs. But I like having the biggest two.gears for long and hard climbs, (Alp du Zwift for example).
So, my question is, if at any time I got stuck and run out of gears, can Zwift simulate in some way a shorter gear so I can keep going?. In the real world, if that ever happens I can finish walking, what happens in Zwift if you can’t cope with a too steep climb?
Note though, that Trainer Difficulty may only be part of what you are looking for. To me it sounds like you are more looking for Increase baseline resistance, which is requested as a new feature very often.