Local theme development

I’m not sure if this is answering your question, but if you’re tracking your code changes (surely you are) with Github, you can connect your Github account to your store and use your ‘production’ or ‘main’ branch as your live theme. Then, every time you push changes to that branch it will automatically update the theme. This is useful for Staging/Testing themes as well if you or someone else wants to QA changes before sending them live!