Q: How do I update Luma3DS?
A: Use Luma3DS Updater
Q: How do I move saves from an existing Gateway setup to device installed games?
A: See this
Q: Can I run awesome homebrew and emulators with this?
A: Yes! Custom Firmware not only enables the Homebrew Launcher, but it also will give you hacks on all versions, which means you keep it forever, even with updates.
Q: Where should I go for support?
A: For support (in English), ask for help at Nintendo Homebrew on Discord.
Q: Can I use a 128GB (or larger) SD card?
A: Yes, but some users have reported slowdowns when using such large sizes. Note that you cannot format the card with exFAT; you need to format it with FAT32.
Q: What about System Transfers?
A: Once you have completed the guide, you can system transfer to and from an B9S 3DS or 2DS exactly like you would a regular stock console or EmuNAND (you will lose any non-legitimate games/themes/DLC in the transfer; saves will stay even for games that are lost).
Q: Help! Something bad happened and now I cannot boot…
A: Please look at the troubleshooting guide.