Update: So, that's a nope. It turns out the particular site that I found which listed the angle of the 5VX belt had a typo! It has a 38 degree angle, not 30. Sure it's slightly better, but it's not right.
This whole time I've been under the impression that it was just the Malsossi Variotop which used the 30 degree belts. I decided to order a Doppler ER3, thinking that it would solve my belt-eating problems. It is also 30 degrees!
Now, I can't help but wonder how others are getting away with using regular belts with these after market variators. Are people just not running as much tension or putting out as much power as my zany water cooled setup?
After doing a bit more research, it seems that industry standard "variable speed" belts (go figure, eh!?) are 30 degrees and will match our variators properly. The only problem is that they seem to come in limited sizes, and are considerably wider. The thinnest available Gates variable speed belt appears to be 3/4", while even the BX belts (which we consider to be wide are only 21/32; a difference of almost 2.5mm, which can make a big difference in the pulley in that you will have a tough time getting the belt to ride all the way in 'low gear'.
Furthermore, because of the wider inner width of the belt (because of the angle) and the already wider top, the belt itself would most likely not fit in to a typical clutch pulley channel!
So um, yep. (edited)