Just replying to tag myself in for replies. I looked into this a while back, and to be honest the quality/compatibility of c4d's gltf export left a bit to be desired. The only way I found to get decent results was to go through a platform like sketchfab and do the export via fbx with animation in the take system.
The problems, animation in c4d's take system is miserable. You need to remake materials in the web editor once exported, so if you need to reexport to update things, you need to redo a lot of your material and lighting work.
In short, we've put our web 3D plans on hold until c4d improves, or three.js improves, or someone learns enough blender which apparently has better exporters.