The time period of duration for QR code login is hard coded and set to 600 seconds. That makes sense and is in most cases a very good setting. In some cases it makes sense to set this time period to a much longer time period.
I had the discussion with teachers from primary schools that work from, class 1 when pupils can't read or write. They have the wish that they can set the time period for a QR code to six months and print the QR code for each pupil.
This is not secure like a period of 600 seconds. But I see the point from their perspective.
We could solve this when we make the period configurable by admins.