Visibility not exported

[imashination]

I am animating the two 'visible in editor' and 'visible in render' options to hide objects, however these changes do not show up in sketchfab. Reading up, it seems visibility animations are supported by other DCC apps. IS this a bug or is there some other way to officially hide objects in animations?

plus a small general question in case anyone can help, is it possible to overwrite/reupload to a project from the c4d plugin? eg. I export a file to sketchfab, apply all my material and light updates, but then need to make a change in c4d, can I keep my changes I have made in sketchfab? It is possible with file uploads but I cannot make the c4d exporter update an existing sketchfab project.