from what I'm seeing here and in the rest of the code, the WHY badge firmware creates these "alias" devices (APPS:, STORAGE:) that automatically map to the microSD if present, and fallback to the flash if not. including for writes.
@LilaHexe I haven't tried yet, but from what it says in the wiki, manifest.json should be renamed to badgehub_client.json and placed in SDCARD/BADGEVMS/APPS/
@LilaHexe that should be simple to check, were the BADGEVMS/APPS folders created automatically after the first time you put the (empty) microSD card in the badge? if not, that's probably the case. in my case, I first put the empty microSD in it and it created those folders for me
@LilaHexe from the dev's answer here, your issues with the SD card might actually be related to a bug in the official firmware (in my case I already pulled the faulty commit off my badge, so maybe that's why it worked)