Looking for a better motherboard.

So I bought the HP Omen 35 L from Best Buy and I cannot tell you the amount of rage I have for this thing. The fact that bios/uefi is so locked down I can barely do anything and the fact that the board itself limits just what I can actually do. I get bottle necks on heavy gaming sessions. I don’t wanna have a glorified office computer. But then again it is a prebuilt. Just wondering what kind of actual motherboards I can fit in this thing. Or if it would be better just to buy a full board and a new case but keep the cpu, ram, psu, and the gpu.