TWLSaveTool VS ftpd

I assume based on your cfw comments you already backup your ds/3ds games, but for anyone googling or searching this reddit in the future... TWLSaveTool can backup your DS games. 3ds has Checkpoint or JKSM. You need homebrew or a cfw 3ds for these.

You could try TWLSaveTool which is an NDS save dumper/restorer for 3DS, but it could be that whatever file structure the emulator used isn’t compatible with the OG cartridge.

Since it's a DS-era game, you shouldn't be using Checkpoint, btw. Have you tried using TWLSaveTool?

If you want to extract the save from the cartridge you can use TWLSaveTool

TWLSaveTool

Rudolph’s GBA backup Tool / TWLSaveTool

you can interact with your SD card without taking it out using FTPD

Run sys-ftpd or ftpd and access your files from a computer using an FTP client

Use FTPD for quick file transfers to the 3DS over wifi without the need of removing the SD card. Available in the Universal Updater app.

FTPD: https://github.com/mtheall/ftpd/releases

I don’t have what you’re looking for but I have a solution for your screwdriver problem. Here is a video explaining how it works.

I have ftpd on my 3ds and I use FTPCafe FTP Client on my Android phone, then i download DS roms on my phone, after this I share internet (hotspot) to my 3DS, start ftpd on it, then put the IP that it says on the phone.