I am trying to create some outline to my object and came across this videowhere at 14:00 it states that this outline requires gBuffer access, which is not available on all devices.
Here I have found out, that the gBuffer is only available on OpenGL 3.3+. Also, if I am not mistaking, OpenGLES 3.0 (Android) is based on OpenGL 3.3. So I should be fine with this outlining method? Also on the second site I linked, the gBuffer is not supported on Vulkan. So I am cutting off on some android devices like Pixel or Samsung.
GBuffer is not available in Forward Shading Renderer which is used by UE4 on mobile. But, according to roadmap, it will be available in new mobile renderer for Vulkan in UE4.26.