I can safely say I've never seen this before.
A modified NVIDIA GeForce RTX 3090 graphics card has been tweaked to work from a laptop and its NVMe M.2 slot, from an AMD Ryzen 4600U-powered Kosin Air 14 laptop.
The modder removed the installed NVMe M.2 SSD that was inside of the laptop, attached an M.2 to PCIe adapter cable, and then connected up his GeForce RTX 3090 graphics card. It wouldn't be a "mod" without some physical modding, right? The modder also drilled a hole in the laptop so that the required cable could run outside of the chassis itself.
Only 4 x PCIe lanes were available to the GeForce RTX 3090 but performance wasn't bad at all. In a quick 3DMark TimeSpy benchmark the GeForce RTX 3090 scored 14,008 which is a little better than a desktop GeForce RTX 3070 in a Ryzen 7 3800X system -- my GPU review test bed.
You do lose performance doing this, but it's an interesting mod nonetheless.