So occasionally, and fairly randomly, the ability to key a mesh on the hierarchy view disappears until the mesh is turned off and then on again. Obviously this undoes anything you had already done to edit the mesh on that frame, and there is an easy enough work around in swapping to auto keying momentarily, but this seems like something you should be made aware of. I attached an image to show the mesh clearly lacking the key icon completely.
Another bug inside of Unity I've had (and maybe it's already fixed, I've just worked around it since I found and reported it, so please let me know) is with the clipping masks. Inside of spine itself, the slot you set as the end of the mask is included as inside of the mask, while in unity it is considered outside. As such my work around has been to make an empty slot just to use for any given clip endpoint in the draw order. If this is fixed please let me know, and if it isn't I'll just make you guys aware again that it exists.
Cheers!
