I pushed the ROG 6 to its limit. Max CPU + GPU load. It hit a whopping 4200mA(~16W, FYI it's 1.5 hour 100% to 0%) with cooler on(using Lv2/3 because no power in). But it quickly in 2 seconds throttled to around 85% of its max performance(FPS drop from 55 to 48 with significantly more judder) while using 900mA less power(still, cooler on Lv2, so total ~12.5W).
It all makes sense because you're on battery, but when you remove cooler, CPU and GPU immediately goes back to its max frequency while using around 9-10W, barely sustainable without any cooler. That, still, makes some sense even though it'll get hot, still manageable hot thanks to better SoC.
The problem is, when you plug in cable with enough PD spec(enough for Lv3 cooler mode while playing at full load and phone is actually charging(read current in monitor software)), the power limit is still there. This need a fix.
Only workaround now is using Kunai 3 with an external cooler.