>>385555716
The fuck you are talking about. SteamVR is the only infrastructure which ALLOWS you to make custom controllers.

SteamVR HDK is available free of charge and is royalty free, gives you all the tools Valve used to design controllers and headsets. 

Hardware development kits are available to buy freely at price slightly higher than a vive tracker. Chiplets and ASICs for controllers are available to buy in mass and documented.

Lighthouse is litterally the most open ecosystem.