Change menu_wallpaper setting from default 'stretch' to 'fill'?

RetroArch General
#1

Just like standard OS (GNU/Linux DEs, Windows, macOS) does?

#2

I mean, custom wallpaper/background uses ‘stretch’ by default can’t solve one of these two situations:

windowed mode (most retro games are 4:3 naturally)

maximized window/fullscreen mode (nowadays monitors are 16:9/10)

So only use ‘fill’ can solve all of these.

Anyone? Thanks.