I submitted an example that reproduces the failure to dispatch protected methods to NI a couple weeks ago and haven't received any reply. Let me know if you're interested in exploring further. (You were also on one of the community threads to which I redundantly posted the example code.)
Also, I'm finding the inability for a privately-scoped malleable method to access class data very limiting. Using accessors prevents some crucial in-placeness optimizations and making the in-place method public makes for a super leaky API. I found yet another (slightly less bad) workaround in my current case, but only by totally sacrificing encapsulation.