But I think: as long as Visionaire is not able to handle key frame animations, the import of various animation file formats is not worth discussing.
PS: It seems there is an universal exchange file format for 2D and 3D animations named fbx:
Isn't that the point of the Spine runtime library? Technically VS already has keyframe animation built into the regular animations as you can select a frame, click on the edit button & from that apply a sound fx or add some custom action parts or Lua script to it - at least I believe in a way that, that's similar to how keyframe works, no? I've messed around with Adobe After Effects before & that uses keyframes & all that did as far as I remember was to allow me to adjust parameters & trigger new things/kill existing things, etc.