I have a Surface Laptop 6 and a Razer eGPU enclosure with a Radeon 6600 XT in it and it works fine. The manufacturer will list what sorts of GPUs are compatible, assuming you get a brand name one and not some cheap no-name Amazon job.
Honestly if you have the money, go for a PC. The mobile CPU in laptops/tablets will your biggest bottleneck. Get a decent CPU, motherboard and PSU and the best GPU you can afford and it’ll probably out perform the Surface.
Meanwhile Costco in Australia is pushing to have penalty rates abolished. They might be good by American standards but they can get fucked trying to erode Australian workers rights.