In that case maybe the answer is $200 in tokens to make a metal OpenGL shim and then share it to the community on GitHub.
ANGLE already does that: https://chromium.googlesource.com/angle/angle
Isn't https://github.com/google/angle just that?
Edit: I guess no, Angle is OpenGL ES. My bad.
Given the comparable performance of OpenGL and Metal on the same hardware I was under the impression that is how Apple had been implementing OpenGL for quite a while.