QML components can't use OpenGL version > 2.x.

For example, if a QML ShaderEffect uses textureGather it will fail to compile because OpenGL version 4.0 is required.

Possible Solution: allow OpenGL version configuration (version AND profile) via .yaml files and appman command line arguments.
A global OpenGL version configuration is the minimum requirement which would set it for all application windows. Ideally a global (for single process) and an app based method to specify the required OpenGL version exists.