The anti OpenGL sentiment is so strange to me. OpenGL is basically supported everywhere even in places where Vulkan is unpopular.

Any sane person who actually wants to do low level graphics programming should rather work on the libgodot effort since it will make it much easier to use Godot as a wrapper around Metal and Vulkan by defining a custom RenderingServer without even touching the Godot scene graph or having Godot own your application lifecycle.