Was thinking of getting a Super DSTWO so I can play DS games on my 3DS XL (bigger screens) but I heard you have to update the firmware on flashcarts through an older DS.
I think that it works usually. I tried it many times (the last time was on the 4.4.0-10) and it worked every time!The DSTwo is special and can sometimes update after being blocked with a special method, but it should not be relied on. Always update the cart first.