On most occasions I use the random function to play my whole collection. It certainly gives some interesting results.
However, there are certain tracks I don't really want to hear in the mix. In my case a couple of good examples are 'Xmas' and 'spoken word', but I am sure other users have different reasons to want to split their collection.
Can I suggest a possible, mayber relatively simple, change ? Is it possible to make alternative folders to the 'music' and put the collections in these folders ? The splitting could be done using an attached PC, if necessary, but it would need a section in control panel to select which folder to use as source.
I can't find anything in the forum to suggest that this has been raised before, although I admit I'm not good at finding stuff. Clearly, it would need some development, but it might address some of the genre issues people seem to have.
There are ways to use playlists to achieve some of these functions, but is it worth considering developing extra folders to run 'special' groups of tracks.