@rolski
The way I handle these type of sets is:-
A) manage each disc as a separate album and either make the title the differentiator or add a version comment (or both if appropriate)
B) in album browser select all
C) edit and group all as alt versions.
D) select the preferred disc as the top of the stack.
When you see these in the album browser (assume show dups is set to off) the the top of the album stack is the one you see.
When you click on that album and click on the “other versions” button, like opening the boxed set, all are clearly visible and easily selected.
This gives me a boxed set type behaviour.
Any good?