Awesome, thanks @a.okeefe289.
You’re correct that Cesium ion doesn’t support a direct GeoTIFF to 3D Tiles conversion. However, I wonder if there’s room for a more custom workflow.
It definitely possible to use a GeoTIFF to create a DEM file. From there one could create a TIN mesh, then export as .gltf or .obj. This can be used to create 3D Tiles in Cesium ion.
Once you have each 3D Tiles dataset in CesiumJS, it’s possible to apply custom colors, and show and hide each tileset as needed.
There has been interest in Terrain to 3D Tiles workflows using Cesium ion, but those tools are in progress and not yet available publicly.