The reason FW limits it is due to sensor measurement errors, to avoid actually pulling more than 240W when the device thinks it’s pulling less. As far as I can tell, that’s not what’s happening to me, so I undo those checks.
And yeah, there’s a total power budget that’s shared between the CPU/iGPU/dGPU. Too much power on one of those can squeeze another component into drawing less power. That power budget can be tweaked with tools like RyzenAdj and Framework Control (on Windows).