Hopefully i'm suggesting ones that aren't already in this list:

* in a modal view - if you click and drag to highlight - which I often do to edit coordinates - if you release the mouse outside of the modal you actually dismiss it and lose changes

* 'set default' in addition to 'reset default' - the logic here would be opposite - set the template's default swatch from an individual keycap level, and prompt user if they want to update all linked keycaps

* only prompt user to "Are you sure?" when there are unsaved edits

* granular control of position at individual keycap level (instead of stepped)

* "edit template" link from individual keycap view