Yes, all you need is implement exporting of bone method. I just called it “skeleton export”, because it sounds better for my taste =D
That’s great! Then, can you please add Scripting to Ideas list? 
And replacement of deprecated classes too (as we got it confirmed by @ice0).
About frame-by-frame animation:
I think that frame-by-frame function should be implemented differently - through switching of exported canvases. This idea is described in my post here (item #2) - Nested animations - #16 by KonstantinDmitriev
Also, what we need for frame-by-frame animation is possibility to create new frames and seamlessly edit contents of exported group.
For example, it would be nice if user can have a group selected and “paint” content inside of it (using vector tools). This is actually, partially implemented for raster brush tool - if you have imported bitmap, you can try to select its switch group (not bitmap itself) and try to paint on it with Brush Tool. The paint will be automatically transferred to Image Layer inside of Switch group. We need something like this for vector tools - i.e allow to create something inside of currently selected group. Like natural painting process.
And now about creating new frames - it would be nice to just have a button to create a new “frame” for currently selected group. Clicking that button will create a new (empty) exported canvas and will switch current group to it.
If we talk about Switch Layer, then I think managing switching of frames could be simpler. Maybe just dragging to timeline any child layer of Switch Layer - this will create a new waypoint at current time?