I tried this, but sadly it doesn't work.
I haven't investigated why it doesn't work though.

No worries, my nrf52840 just showed up so I'll investigate

@mikesmitty any update on this? I would really like to have it for something... 😸

Oh yeah, this fell off my radar. I've got a debugger just about set up with an nrf52840 now so I can dig into this again

Ok, at least in my testing it looks like it's just a problem with m.buf being too small. My test device has a write block size of 4 bytes, which I didn't think would ever happen. The m.buf buffer is set, perhaps a bit naively, to use the write block size as a capacity, but it needs to be 64 bytes at a minimum to be able to store a full usb packet and it's panicking. #5017 also modifies these buffer sizes but in a more expansive way so this will likely end up just being a temporary patch. I just saw Ayke commented again on that one so I'll swap back to that one next

Pinging Dr. @mikesmitty 😸

Sorry, been getting distracted a lot recently haha. I'll start working on this again this weekend

Thank you!