OK... I've done some more digging, and more importantly listening, I still think it's AFX.
But I would be totally just as into it if it were someone else.
I get the whole it could be Squarepusher or MikeP or... whomever from that era, but I have trouble accepting that anyone but AFX would sit on a treasure trove like this for that long. I love MikeP to death, but his archival material that he has released isn't in this style at all. While this is slightly funky at times, it doesn't go anywhere near SquarePusher levels of Tom-foolery (sorry).
I love the idea that this could be either collaborative pieces or a dumping ground from like-minded folks from that era, but it's too seamless from track-to-track.
Feels like one mind is behind this. Though, god, if this was the Braindance collective reuniting that would be lovely.
Maybe Ovuca?! Been revisiting the Astrobotnia albums. Absolutely some of my favorite IDM of all time.
But again, with AFX it makes sense that he would be sitting on all this. With anyone else it doesn't.
For anyone curious to go down this hole deeper, here are some interesting bits...
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https://www.facebook.com/brainwaltzera/>
interesting thread here that argues against it being RDJ
https://www.reddit.com/r/aphextwin/comments/2undvc/brainwaltzera_soundcloud_account_is_this_aphex/
the plot thickens... the post from May 5 2015 has interesting insights...
http://forum.watmm.com/topic/85636-richard-d-james-soundcloud-a-gift-to-the-fans/page-386
There is a "Who is Brainwaltzera" Facebook page that I couldn't find any clues on...
https://www.facebook.com/brainwaltzera/