OSX Mojave openGLContext.attachTo() issue if more than one context is used

There is not a great answer for this in JUCE currently.

Some of the OpenGL issues were introduced recently and seem to affect M1 machines acutely: Poor performance with OpenGL Renderer on Apple M1 machines

For certain types of rendering, Core Graphics can be much faster that OpenGL, but not for more complex scenes or fast animating visualizations.