Unless I’m mistaken there is no way to make this sensor report a modified value (mine is 5 deg. low). I am wondering if there is another way to do it. With some Luup code or something?
I’m looking for the same, is there a way to add a new service to devices that you can enter an offset value into?
Me too. My Multisensor6 is reporting almost 3 degrees too much 
According to the manual, you can adjust the offset, but have no idea how to set these values. See attachment from Aeon Labs user manual.