I don't think that the developers don't like if anyone report bugs to them. I think you're wrong about this. If you read into the cncdrive forum ther are even rants which are still there and were not removed.
So, if they warned you about something then I am sure that it was not about you posting bugs, but the way you wrote your post(s).
But it is understandable if you want that company to look bad when you selling the concurent products, it is helping your business if you do so.
I don't think that the Acorn can have higher flexibility than the UCCNC, it has 4 axis only and some annoying PLC language, no screen editor, no access to GUI things, nothing can be modified like what can in the UCCNC.
So, I will sure stick with the UCCNC for now, it works absolutely fine for me. I'm not interested in buying a more costy product with less features and less flexibility.