Mobile HQ reflection option does not use the sky reflection cubemap.

See attached image., the selected sphere is using HQ reflections. HQ reflection code does not look for sky captures. Note that the sky capture does not require the parallax correction code.

Create simple project, add a dynamic skylight and 2 static meshes.

Create a material with a low roughness and apply to a mesh.

duplicate the material and set HQ reflections (forward renderer options)

Switch to ES3.1 preview mode.

observe that the HQ reflection material does not reflect the sky capture.