Can ExtrudeGeometries be merged?

I am trying to merge 2 TextGeometries, which I believe use ExtrudeGeometries behind the scenes. Can ExtrudeGeometries be merged into one mesh (like BufferedGeometries can) in order to reduce draw calls?

Personally, I always use BufferGeometries, which allows you to use BufferGeometryUtils.mergeBufferGeometries

Could you use THREE.TextBufferGeometry instead of TextGeometry ?