I’m probably a bit late with this but I’ve been using a transfer plate for over a year now. Originally I was going to have a ‘step’ that came out but apparently the vehicle clearance wasn’t enough.
Once I get used to ensuring I’ve put the plate up before shutting door, all good. Mine is on a WAV and definately made a positive difference for me.
Even when I shut door forgetting to put up the plate, it bounces without problems off the door but I don’t have fancy door interior so no damage is done. It’s easy enough to remove and put back if need to.
Obviously cheaper for Motability on adaption costs compared to motorised seat, etc,