Ohhhh I thought there was gonna be a new one that made it dim.
I don't find the current HDR Game mode to be dim at all but I also never had the TV prior to that update.
Played through all of Horizon, Uncharted 4, and both Infamous games.
I did have to turn up the in game brightness in Infamous. Otherwise no issues.
I have my OLED in a fairly dark room, if it matters. Dynamic contrast off.
Compare it with the other HDR picture modes.