Well, looking at the rest of Ashley's reply, it sounds like this could be seen as a limitation of chrome, or of C2, depending on how you view it.
On chrome: I would leave a comment on the following thread requesting that chrome be allowed to allocate >6400 images at a time, as long as it is explicitly requested to do so:
https://codereview.chromium.org/18541
An even better approach might be to file this in chromium's issue tracker:
https://code.google.com/p/chromium/issues/list
As long as you can give a good case for where it would be useful -- and it sounds like you can -- you've got a decent chance they'll change it.
The comment about 'Windows has a hard-coded limit of about 10,000 images per app' sounded like gobbledygook to me, but apparently it's true. Seems like this could be worked around by having C2 spritesheet objects with 100> frames total between all animations, but that brings us around to the infamously inflexible C2 IDE...I see another C3 feature here.
10,000 is a lot of frames, but if you break it down it really doesn't seem that excessive...if your sprites average 64x64, with no downscaling -- not uncommon for a pixel art game -- 6400 frames would break down to 16 1024x1024 spritesheets, totaling 64mb of memory...you should be able to get away with that even on most mobile devices.