Jumping strait to a World Instance view from a "Friends" wing set to "Location" sort mode opens the Main UI without loading the background effect on the first open of each startup.
(Clicking on an Instance not a User)
Opening another page on the Main Menu loads the background for the already open Main UI
steam-audio-beta & open-beta
Proton 10.0-2 (beta) & GE-Proton10-15-rtsp18 & Windows 10