Other GBA dumping method.

For dumping both GB and GBA carts I personally suggest the GBxCart RW. It is a very useful hardware (not too expensive), in active developement, that can also extract photos from Game Boy Camera, read/write repro/fake carts, etc.

I use it since 2019 and I love it.

GBxCart RW (Gameboy/GBC/GBA Cart Reader, Writer & Flasher) – insideGadgets Shop

For GBA saves I like using a Raspberry Pi connected using the GPIO pins to a link cable. Basically a old Xboo cable but using the GPIO instead of a now obsolete parallel port.

https://github.com/akkera102/gba_01_multiboot

Just compile SendSave.c in place of multiboot.c from the instructions.