OK. But, when I switch themes (or if I allow a user to choose their own theme), then am I not faced with the problem that I need to make sure each theme is 1) editable so I can add the new head tags and even worse 2) need to maintain my code across all themes?
When I started using different themes, some indicate that to edit the theme you need to modify the github repo. This seems really onerous and inflexible. But, maintaining my script tags across each theme seems very error prone and an even bigger problem.
What am I missing? Is there a way to resolve those problems only by using themes?