If the world was more organised and most cars were taking 12 weeks or less (about normal ish?) then I don’t think it would be too difficult to time a delivery so that it lands on a brand new plate. Dealers often try to set it up so that they get sales on the 1st of the month as it will benefit them as well as the customer.
I’m not sure if that really applies with shortages of parts and cars not being built quickly enough to meet the demand. I’d imagine dealers want to get the cars out of the door as fast as possible then onto the next one.
I don’t think motability will care in the slightest about the difference in resale value between a 72 plate and 23 plate in 3 years time. They operate on a much bigger scale to be concerned with that.
an interesting point is that there are 6 months between a new plate so if you don’t want to accept a car in month 5/6 when would be the last time that you would? 4/6? 3/6?
You have your reasons for wanting a new plate which to me is fine and doesn’t require an explanation but I do think it’s going to be difficult to get everything to fall into place for you in the current climate so it might be worth compromising