How to use Bluetooth hid

when exactly is boot0.js executed

Just at startup. However because Bangle.js tears everything down between apps, that's basically every time you start a new app.

so when HID is not enabled in settings while starting and boot0.js is only executed on start the NRF.setServices() never happens, correct?

ish. The second you leave settings after setting HID to true, it's a new app (the clock) starting so it then gets called.

What Linux receives is:

Interesting. So what actual bytes are you sending in order to get that?

edit: Also thanks for the parser - that's really handy!