OK, it sounds like the way I was starting Bluetooth doesn't work properly for Libra 2. I'll modify the descriptions to clearly state it's not tested with anything but Clara 2E. I don't have a Libra 2 device to develop this further for the other devices unfortunately. Thank you for testing this and I'm sorry there isn't a satisfactory resolution.
---
As a side note, this means the missing piece is "turning on bluetooth via KOReader", this means turning it on from Nickel and then running KOReader would have your clicker working.
You can comment out the portion where KOReader kills bluetooth on startup, documented here:
https://github.com/koreader/koreader...ent-1791789778
But this means bluetooth will never be turned off and will drain your battery quickly. You can even delete the folder bluetooth.koplugin as all necessary changes are already in device.lua file already.