NGFF V8.0 EXP GDC Beast Laptop External Video Card Dock Notebook PCI-E Expansion Device - Prime Tech Mart
Theoretically the M.2 port could be used to attach an eGPU (maybe for better performance on "desktop mode" ) link in the comments : r/SteamDeck
Amazon.com: JMT EXP GDC Notebook External PCI-E Discrete Graphics Beast Series External Laptop Docking Station Mini PCI-E/M.2 A Key No Power (M.2 M Key) : Electronics
Mini PCI-E to M2 adapter, to get more than pcie x1 is possible ? : r/eGPU