> And there are homebrew/piracy cartridges that fill that space with 32mb of ram.
There's even an official one, the Opera Web Browser came with a second cartridge for the "GBA" slot to add 8 MB of RAM and a MMU: https://en.wikipedia.org/wiki/Nintendo_DS_Browser#Memory_Exp...
(I've long lost the Opera DS cartridge, but the memory expansion is still in my DS Lite as a slot cover)