Note that R4i Gold 3DS RTS flashcarts will not be able to be used for their standard functions (such as launching `.nds` files) while the ntrboot exploit is installed on it. This does not apply to the Acekard 2i.
There are optional steps at the end of the ntrboot boot9strap installation instructions to remove the ntrboot exploit from your flashcart when you are done.
This method requires temporary access to a second 3DS family device that is already running some kind of custom firmware (such as boot9strap or arm9loaderhax). It is compatible with the following flashcarts: