So it appears that you have curated the tracks list and the genre's playlist too.
Max tracks in each is 2000 , probably the playlist length limit of RB. If I even give you the benefit of the doubt and say that 'tracks' has only tracks in it not in the genre lists (very much doubt it though), then there is a possible maximum of 32 x 2000 = 64000, otherwise 62000.
Ok so I can go to beatport; make playlists and come back to have tracks not in these lists. How do I know they're not? I don't.
Can I search for a track not in those lists manually in RB? I can't test this as it's impossible to memorise 2000 tracks go to beatport find 1 definitely not and come back to see, without knowing your algorithm as to how these lists are generated, when they may update on their own etc it's totally mind boggling. I suspect most downloaded/bought/whatever Beatport ranks them as.
Beatport have stated that through link and cloud you have access to some 3 000 000 tracks & I have searched and found tracks on beatport that are not part of the scheme, so how representative are these lists?
My suggestion would be something like if you import from the list to RB then the beatport list removes said imported track and grabs another from the database, but again how do you filter this? If it's always by popularity then everyone has the same set and that's just boring, so it needs to be really random on the selections in order to throw wildcards that people like me find by accident. If I want that track everyone knows, guess what? I know it, so can search it manually, it's the stuff you don't know that's the most interesting here I feel.
Also Dubstep seems to be empty, 0 tracks. I don't know yet if this is the only 1 like it.
So it's obviously a little more complicated but there is a bug here where some playlists won't load at all and some won't load a full 2000. I have seen the progressive house genre list be 2000 tracks before I just restarted RB and now it only has 900. Many lists were not loading including Dubstep before the restart and now they have tracks in them, but not all have 2000, some stop at 900, 1 at 5or600. it's random for each launch of RB and the 1st lists you hit seem to load correctly.
Hope that this is helpful