A part of me thinks you knew this was a possibility. Both cars are practically the same.
To reject this car is of course your perogative but if the 20" wheels sort the problem I can't see the issue. These cars are designed to go off road therefore pretty 21 or 22 inch wheels is (imho) just "tarting" up the car.
You use the car for work so comfort is very important not bling (unless your job entails pharmaceutical distribution)
If you reject the car then I think JLR relationship is over. I think and admire how they've bent over backwards to accommodate you. Don't think Volvo would have been so accommodating. Lexus dealers are superb. Talking of Superb.....there may lie your answer
Having just looked at JLR website I notice the Velar first edition comes with 22" wheels as standard. So wtf are they playing at. Surely this car was tested to death so I find it very hard to believe yours is the first they have noticed this noise. So maybe walking away may be the better option.
The new Porsche Cayenne looks great imho. As does the Audi Q8. Got to admit 1st world problems can make you smile.