How to build an Android APK with OpenGL ES 3.1

I am working on a GearVR game and developing it with a Samsung Galaxy S8+

I am desperatly trying to build an APK using OpenGL ES 3.1 (and not OpenGL ES 2.0)

I have followed the instructions on this page: https://docs.unrealengine.com/latest/INT/Platforms/Android/OpenGLES31MobileRenderer/
:
1/ this page does not explain how to actually build an APK but just to launch the game on the device while it is connected to the computer.

2/ when trying to launch the game on the device:
a/ the console indicates that an OpenGL ES 2.0 version is built and not an OpenGL ES 3.1 version
b/ the game doesn’t play (just a black screen)
c/ the building process takes forever
d/ the ETC2 compression is used instead of the ASTC compression

So here are my questions:

1/ Why doesn’t Epic release a version of the Engine which natively builds APK for OpenGL ES 3.1 instead of letting us manually compile the engine?
2/ What would be the process to actually launch the game on the device and have it work ?
3/ What would be the process to make sure that the build is actually an ES 3.1 version (and not ES 2.0)?
4/ What would be the process to build an actual ES 3.1 APK instead of just launching on the device?
5/ What would be the process to make sure that the ASTC compression is used instead of ETC2?

Thanks a lot

Did you figure out the answers for those questions? I’m also a bit stuck with ES 2.0. Is there a way to check on the phone if it uses ES 2.0 or 3.1?

I followed every instruction in that page, but I still got armv7-es2 compiled instead of armv7-es31

I can answer some of your questions.

I found that even though you enable es3.1, the *.so and *.apk files will also have “es2” as postfix. I use Feature Level Switch node in a material to check that.

Is there any way we can override that postfix or force it to use ES3.1?