Oh, sure, you can now fake an USBMS session without any actual user interaction.
c.f.,
UNCaGED for a similar (albeit slightly more complex) use-case.
For your use-case, something as simple as
Code:
echo "usb plug add" >> /tmp/nickel-hardware-status
button_scan -pu
Would probably do.
(See
FBInk for button_scan binaries).
You could then arguably stick that in a shell script triggered via a KFMon icon, and it becomes computerless. Not painless, because the fake USBMS session takes time, but, that's currently the best we can do.