Funny thing... They seem to have fixed this issue in the new Focusrite Channel Strip

They have added optional calibration settings... and most important: The two meters CAN BE calibrated properly against each other... IF you know what you're doing that is (aka set the meters to the standard of 0VU = + 4dBu against your preferred dBFS setting of -18dBFS or -20dBFS... or whatever you like).

Disclaimer: I have NOT demoed yet, so it is all from what I could get from the video below
And maybe this will port over to the other channelstrips (maybe there's a silver lining )

https://www.youtube.com/watch?v=tSRPBMgP88M