How to disable letterboxing and adjust UI5 for the widescreen?

Question

I have an UI5-based app (1.66+), which works correctly, but there are huge empty spaces on the left and right sides of the screen (aka letterboxing is on):

Answer 1

Static implementation via XML-template:

For dynamic implementation via JS-controller with appWidthLimited: false in sap.m.Shell, see: https://stackoverflow.com/a/55867413