Well, there is partial source code and apparently some dude has rewritten the missing parts and is releasing builds of them with new features known as NewDark, but he doesn't want to open source his shit either.
Portable Steam Deck Dock: NewQ 5-in-1 USB C Dock with TF Card Slot, HDMI 2.0 [email protected] Display, 2*USB-A 3.0, USB-C PD 100W Max, Steam Deck Stand Base Accessories, Supports Other USB-C Devices and PC https://a.co/d/4FBfHu1 Kinda dope