That's not true, and I would still like to see your evidence of such accusations...
FW: 4.7.5.1.83.8.204.1.11
The problem is that like I say, there is no evidence. There have been suggestions made but no hard and fast facts.
I have that firmware on my HH5A and that does not give G.INP support. I can easily demonstrate this by swapping between my HH5A and HH5B.