You can add xkb-options to your gnome session in dconf as org.gnome.desktop.input-sources.xkb-optiions
org.gnome.desktop.input-sources.xkb-optiions
You can find them at /usr/share/X11/xkb/rules/base.lst
/usr/share/X11/xkb/rules/base.lst
Two I like are:
shift:both_capslock_cancel
ctrl:nocaps