GlosSC or Global SteamController is a small set of tools that allows you to use your SteamController as a systemwide XInput-controller alongside a systemwide (borderless window) Steam overlay
A: The overlay only works for windowed or borderless windowed mode applications. Nothing much I can do here.
This is even true for UWP-Games! While it's true that UWP doesn't run exclusive fullscreen, they don't run, strictly speaking, classical borderless window either
* The "GloSC-GameLauncher" which can launch Win32 and UWP games and mainly exists to work around dual overlays
* The "SteamTarget" which does most of the magic - Showing the overlay to the user as well as talking to the ViGEm-driver for systemwide Controller emulation