Hey Matt! Thanks for the reply.
I managed to figure out a solution / workaround to the problem by pulling my GLB into Blender, expanding the scale of it, and then using the Blender add-on to upload that new file directly to Cesium Ion.
I’m not sure if the re-scaling or the new upload method was the key - the GLB was quite a bit smaller than the physical size of the capture, so I think some of the faces may have ended up smaller than the 3D tile system was able to handle. But it could also just have been some magic from the add-on. Do you know if the code for the add-on is publicly available?
The viewer that I was using doesn’t use CesiumJS - it’s a tool from the NYTimes for combining Three.js and 3D tiles. I don’t think the loader/viewer was the problem, though, because I saw the exact same errors on Cesium Ion’s internal viewer.
Anyways, thanks again for your help!