if there's more headroom, why is this the same tiny one for pretty much all the recent radeons? going through your reviews, the oc for radeons is by a quick check ~3% throughout their stack, while nvidia is more like 7-8% or even more?
Voltage is limited in sake of that great efficiency. The same goes with RX 5700. But look at RX 5700 xt, 1.2V and 200MHz more clocks than this. Heck you can't even OC this as high, what the clocks for RX5700xt are at stock.