Please try what Mike said sman118, and if you think there's a bug preventing it from working, send us the project files to , so we can look into it.
Will it be possible to simply over-write the Spriter files in the c2 project folder each time, or will they have to be dropped into the c2 editor for this to work?
Yes, you will be able to overwrite the spritesheet and spriter files each time, rather than reimporting.
— asking about mesh deformation. Trust me, I understand your eagerness and/or frustration with the wait, as it's been on my personal wishlist since before I was working on Spriter. Unfortunately, even though it probably seems like mesh deformation is almost done as is, for various reasons it will instead be coming to Spriter 2, which is still in very early development (and for those who don't know, will be a free upgrade for owners of the current Spriter Pro).
Mesh deformation is just not quite as complete as it looks on the outside, and the amount of time it would take to complete it would delay the much more powerful, flexible, and performance tuned version that will be coming to Spriter 2. Thank you, everyone for your patience, and I apologize for the repeated delays. We will do our best to make sure it was worth the wait, and I will keep everyone up to date once we're close enough to start giving ETAs.