I have 324 custom moves unlocked, so I'm pretty far along. But it seems like it got significantly harder. After doing all the classic/all-star/smash run every-character challenges, I already had around 250 moves or something like that. I did Classic mode a little bit and it was ok, but very inconsistent - at times I would get 3 or 4 new moves, others I would get nothing.
So I switched to doing Smash Run. On the first row of characters, I was missing one or two moves for most of them. Bam bam bam, two or three Smash Runs apiece and they were all finished. Next row, it went slower, still haven't finished a couple of the characters. After that, I can do five Smash Runs without getting a single new move.
I've tried doing trophy rush, and it was ok, I can't seem to get more than 4 custom parts in a run though and usually I won't get a new move. But it's half the time of a single Smash Run and less than a quarter of the time of a Classic mode (when you add in the time to do the roulette trick and the credits, each run is not that quick even if you beat the levels very quickly), so maybe it's worth trying a little more.
What the hell.
I'm gonna try the Target Blast thing a little bit today. It's a little frustrating since it can be hard to hit the custom part, so maybe I'll try only going for easy to hit ones.
Sakurai ought to patch this, IMO. No way something that could be required for the tournament scene should be this hard to unlock.
Whatever on unlocking the hats (that's the other thing I have to finish out to get the last challenge) and outfits (I have all of those), but custom moves should not be so difficult.