That's the thing though, it's not the same part. The 4090 laptop is using the same chip design as a 4080 desktop (which is why I wonder why they didn't just call it a mobile RTX 4080 since really that's what it is?)
There are people who've done this in the past -- they'd take that mobile GPU (which back then was like a 40 or 50W GPU), overclock the piss out of it to get it up to desktop clockspeeds... and either add massive cooling to the system, or not do that and then wonder why it was crashing after about 30 seconds. Of course now, there's already a laptop "4090" spec'ed at 150W so I don't know how much higher you could really go -- I do wonder how many people overclocked those GPUs back then only to blow caps and power ICs on their laptops by drawing like 2x the power it was designed to supply.