I haven't made any mods to the laptop because if I open the bottom cover, I will lose the warranty, so for my benchmark, I use performance mode, throttlestop, and NVIDIA Inspector clk+200 mem+550. As for cooling, I use a table that I make holes in and put a fan under, and I put foam between the laptop and the table that surrounds the edges of the laptop without blocking laptop vents, and make it airtight, so the air generated from the fan will be forced into the vents. It sounds simple, but it really works! and my max temp was just 66.(i can change the table with a proper acrylic but as for now i will just using my unused table)
My gpu power can reach 128 watts, maybe because my cpu uses less power than yours and the rest of the power can go to the gpu, but the gpu doesn't want to take more than 128 watts no matter how I try it. Changing vbios seems to only change the boost clock that can be achieved with OC. I have also tried Vbios 150W, but nothing changed.