I know i know, 'use imgmount'. But my motivating example is a bit more complex.

I want to have both the dos and scummvm versions of discworld 2 running off the same data. Normally this would be impossible since they expect the data to be named differently in different locations, and then, dos expects them in cds. However through the magic of hardlinks and mounting a dir as a cd in dosbox the data can be shared without any wasted space.

There is just one... small problem. The dirs have to be mounted on different drives - and i expect the game will not be happy about that - because the only mount command that supports 'disc change' is imgmount - even though mount recognizes that something is up if you try this:
mount d "cd1" -t cdrom -label DW2_CD1
mount d "cd2" -t cdrom -label DW2_CD2
'MSCDEX: Failure: Drive-letters of multiple CD-ROM drives have to be continous'

So it could be detected

Is there any active RFE for this feature? This is not the only game in which i expect this to happen in the future with dosbox and scummvm, for example RAMA. I think this happens with Broken Sword too.