Thanks for the detailed question.
So, right now you are making a kCGLPFAOpenGLProfile, (CGLPixelFormatAttribute)kCGLOGLPVersion_3_2_Core, // This sets the context to 3.2
Which the stock Syphon Server does not handle. There are forks of Syphon which handle OpenGL Core Profile.
Apologies, we’ve been slow to uptake Core Profile because many of the Host Apps and underlying technology hasn’t moved to it (Core Image, Core Video) – and plus were lazy and don’t get paid to do this, haha.
Thanks, and sorry stock Syphon doesnt handle that for you. We should get on that asap!