Motabilty have agreed to customers changing their cars early for lesser reasons than this. Given the incredibly low mileages that many Motability customers seem to do, this car doesn’t seem like a sensible choice, although nobody would know that until they have one! I have a feeling that they would agree to you changing but, of course, you may have a long wait for a replacement car if it’s another lease vehicle.
I don’t know whether Motability is the only option for you, but if you are a very low mileage driver there may be more cost effective options by going private. My daughter has recently taken delivery of a new car (private purchase) that was only 3 months from order to delivery, and it is a model with all the chip heavy gadgets and features that we are often told are the reasons for prolonged delays of Motability cars!