Hello,
I just wanted to tell you that at Naker we are searching for dds files. So we took the liberty to use the ones from this list: BabylonJS-glTFLoader/src/images at master · sbtron/BabylonJS-glTFLoader · GitHub
But we also created others using IBL Backer thanks to that great tutorial: Use a HDR environment (for PBR) - Babylon.js Documentation
So here are the resulting dds files if you want to add it in the Babylon list! 
dds-list1.zip (3.6 MB)
dds-list2.zip (2.8 MB)
dds-list3.zip (2.7 MB)
