Atari Jaguar carts - either desolder ROMs and use ROM programmer, or use a BJL-modded jaguar and the bjl_dump homebrew
Create GBA e-Reader guide
Create guide for Bandai Wonderswan. OSCR adapter requires harvesting cartridge slot from a real Wonderswan. There's also a Tengu cart reader. A flash cart in the early 2000s named WonderMagic could also dump carts, but it's now extremely difficult to find. Carts are secured with two T6 Torx screws. Make sure to not include save data in dumps.
This blog post could be useful for decoding game IDs
General: more “TapeDump”-like homebrew for different systems could be useful. Especially if paired with cheap hardware to allow easy and safe cart swapping.
General: Look into clone consoles that have external storage + cart slot, if they exist
General: Look into if using tasbot/ACE could be more affordable than flashcarts, for running homebrew
GB/C: Dumper for GameCube via Game Boy Player or Game Boy Link Cable. There are GBA methods, but do they work for GB/GBC?
It may be a good idea to overdump (dump past the maximum known capacity) from some carts on some systems, to make sure all the ROM is dumped (even if the capacity is written on the ROM chip), and then analyse the overdump to find the actual size. Maybe this is something that could be done by the dumping hardware itself - maybe make suggestion on OSCR github discussions.
Some carts may have DLC in the save data. Add a note to the dumping guide pages about this.
Rewritable Hard Disks and Flash Media: add instructions on how to censor personal information without altering the surrounding data structure (e.g. FF/00-out file contents without modifying the filesystem metadata or shifting data)