I personally think that for standard non adapted cars that there is a bountiful choice of vehicles up to £1000AP.
There in even just under 60 which have zero AP. Remember grants are there to assist you into obtaining transport to which they deem meets your needs, not you wants.
A £1500 AP is only saving just under a £1.50 a day for the duration of your lease.
Electric will be the norm very shortly, 2030 is only 57 months away. I also believe that by 2028, that Motability choice will be nearer 80% Electric , as manufacturers wind down all petrol and diesel, inc standard hybrid models.
All current plug in hybrids and diesels are all over £2000AP.
Financial suicide to develop and bring a new model into production for a very short period of time.
Driving Electric just takes a bit of journey planning.