No. Gateway consists of two cards. One card (which is basically a run-of-the-mill flashcart) that primes the 3DS to be exploited, and then another which acts as the actual flashcart that has the ROM on it. You can install Gateway with an R4 card, but you can't run ROMs with just the R4.So is he running roms from the DSTWO? Im not really sure the Gateway stuff works.
Are you sure "any ds-rom playing flashcard"? I doubt.yes... the gateway installing exploit, which can be run from any ds-rom playing flashcard can be installed up to 6.1 (or was it 6.2? whatever, doesn't matter)
but the red card, which holds the 3ds rom will only work till 4.5