I can consistantly hold 100W in the low 80C range continuously. But the CPU can hit 130W if I dont set power caps and let it hit 90C+. I also use a fan curve for my 100W load, not 100% fan speed. I haven't done prolonged testing where I let the CPU hold 90C+ though. you will definatly get throttling if you run the cpu at 180W, although a 180W "TDP" might pull a lot less with undervolting and tuning.Please tell me how much maximum W can it withstand at maximum cooler speeds? I want to insert a ryzen 9 9950x with a 180W TDP into such a configuration.
I would guess you will be OK with the 9950x with a heavy undervolt and max fan speeds. I would also look into a delid with the thermal grizzly heatspreader and liquid metal as it may give you a bit extra headroom.
I almost never see 100w+ in games which is why I set pretty agressive power limits.