No, it's not possible. You won't find 3DSs in store still on 4.5 anyway. If you live in the EU you can return anything within 14 days as long as its in good condition even if its opened. You could try opening and returning until you get 9.2 or below. It's a bit unethical though.
Don't give out incorrect info. You can by looking at the serial. And you can still find 4.5 and lower 3DS XL's here in Portugal at least, brand-new, sealed. It all depends on your country and your market. Our economy is tiny, hence stores still have a lot of old stock.