I'm not really attempting this but could it be possible to install an AIO-cooler or custom loop without using a tophat? This would omit a discrete graphics card but if I'd survive using a iGPU it's an interesting idea to me.
Some kind of a bracket with similar mounting to a GPU io-shield holding the radiator assembly would be required. 45mm worth of thickness clearance could give enough space.
Some kind of a bracket with similar mounting to a GPU io-shield holding the radiator assembly would be required. 45mm worth of thickness clearance could give enough space.