So Pygame based EGL + OpenGL-ES1 context works with PyOpenGL 3.1 under Kubuntu amd64 with MESA EGL/GLES. Yay.
Really do need to get a couple SD cards ordered so I can port to the Raspberry Pi too. I expect that will be a matter of just getting the proper library-names defined in the platform loading code. Likely should rename the "egl" platform to "mesaegl" too, as I expect we'll need to differentiate between the various EGL/GLES platforms.
It seems like it might be possible to make an OpenGLContext base context for EGL too (basically a Pygame context sub-class that just initializes via EGL instead of the Pygame GL flags). That's not all *that* useful for testing, however, as OpenGLContext's code always uses full GL for rendering. Anyway, enough OpenGL playing for today, I should get back to paying work.