So far it does not. While GLTF does support double sided surfaces FME does not support this functionality in it’s writer - neither the GTLF writer or the 3DTiles write it seems.

I created an idea for this a few years ago. My guess is this will get added when Safe Software decide to upgrade their 3D Tiles writer to support 3D Tiles 1.1

I forgot the actually link the idea in my comment. Oops, here it is:

thanks，but  fme not support