Add more layouts to use at upfront

Hello
I would like the option to make another layout eg: 1600px wide, but I cannot find how.
I edited these files:
Panino: main-header.php (global-regions/main-header.php)
Upfront: class_upfront_grid.php (library/class_upfront_grid.php)
where I added lgdesktop (Large Desktop, 1560px)
I beleive there are more, but I cannot find
Please advise