Using world-aligned textures for roofs

[LR]

I usually texture my roofs with the following rule, which textures them all using the basemap:

RoofTextureFromBasemap --> 
  setupProjection(0, world.xz, Map_Size_X, Map_Size_Z) 
  set(material.colormap, Map_Path_Aerial)
  projectUV(0) 
  translateUV(0, -Map_Offset_X/Map_Size_X, -Map_Offset_Z/Map_Size_Z) 
  scaleUV(0,1,-1)

However I need to use the buildings in ArcGIS Pro and it's causing some trouble:

• leaving the rule as-is/exporting it as RPK doesn't texture roofs properly in AGP - the offset and resolution seem to be off
• exporting the buildings in Collada Format and importing them in AGP removes the textures
• exporting a building to KML works and displays (flipped) in Google Earth, however AGP simply tells me the file "cannot be used" without additional info. It's also rather large.
• exporting them to GDB (multipatch) and importing them in AGP works, however the file size ends up huge - roughly 100 buildings result in almost 5GB, which I'm pretty sure is due to the basemap being saved completely for each feature

Now to the actual question

I clipped the basemap in ArcMap using the building footprints (see attached image) and would like to texture the roofs using the world-aligned clippings. I think I went through all possible projection setups and scope aligning available, is it even possible to use the textures this way?