1.3 brought so many amazing new features that I’m a little reluctant to request a new feature so soon, but the one feature I was hoping to get in 1.3 didn’t happen: disk labeling. I’ll give two examples of where this feature would help. First, lets take the album “Aerial”. This album is a 2-disk set consisting of two disk-long works entitled “A Sea of Honey” and “A Sky of Honey.” Right now there is no way to label these pieces and one can only identify the sides as Disk 1 and Disk 2. An even more sophisticated use of the feature would be with sets like “The Beatles in Mono” where individual albums are bundled together as a box set. Right now, you can enter the albums as separate albums or as Disk 1, Disk 2, etc. of the box. But there is no way to indicate which disk is which album. Although it would be great to be able to have the full Roon description of each album, that would be too much to ask for. I’d be totally happy if all I got to do is to change “Disk 1” to “Please Please Me.”
A big +1 for this! 
+1 - the ability to be able to give a title to a disc in a multi-disc set would be very welcome. It would also make things more logical when browsing through my recordings of the BBC Proms to be able to see “Prom 1 - 17 July 2015” instead of Disc 1…
+1
As a part of greatly improved box set handling, disc labelling would be essential, along with support of nesting of covers. Scenario: the gazillions of “original album box sets” on the market. We need one overarching cover and box name (probably that from TiVo) and at the same time each constituent album cover and name within that (perhaps also from TiVo but potentially also editable).
An album in such a box set should be connected to the same album on a single disc, as well as being in the box set.
+1, including for the improved box set handling (obviously 
).
I requested this almost 2 years ago:
By the way, I have noticed that a number of feature requests keep popping up when the feature has already been requested, discussed and often buried in the forums. Further organisation of the feature request forum would prevent this and would help the user base to communicate, rather than post separate threads asking for the same thing. I had asked the devs about improving the feature request forum in this manner elsewhere, though as of yet had not had any reply.