[wheemer]

Yes they occur in the official build too, no they cause no problems at all.

It's an old HP with no bios update that I can find (which I found would likely fix the issue)

I found something about changing the loglevel to 3 to get rid of these messages, but I just can't figure out if that's possible.

Where are those messages appearing? Once at boot (hidden behind the splash) or constantly?

mount /flash rw edit the relevant config add quiet loglevel=0 behind it - try 

 Thanks that worked perfectly, now my libreelec no longer looks broken!