Serial: XAW700072*****
Serial on device matches serial on box: Yes
Region: USA
Firmware: 3.0.0
Color option: Grey
Store: Ebay Seller
Was a bundle (if yes, which): No
Purchase date: Mar 9, 2018
Northborough, MA Walmart. Might've been the last one though, the only other two I saw were from much later production runs.
edit: Think I also saw a black QW1038 (?) at the Toys'R'us nearby, if you want to take a chance.
Just picked up a QW4023 New 3ds Red from a Walmart in Central Massachusetts, can confirm it has 9.0.0-2u like QW4025 and QW4024.
Version Number QW4023
Region: USA
Firmware: 9.0.0-2u
System Color (checking a hunch): Red
Wait, if you have a gateway, can't you just load your backups onto the blue card and then reinstall the exploit whenever you want to go back to 3ds games?