I’m loving that the new template helpers don’t require a reload, however I’ve kept all my template entities in yaml due to the ease of bulk editing in code. I have many sensors with similar templates. It would be amazing if either a UI were made available for bulk edits, or if these helpers existed in a yaml file that could be opened in the file editor (like automations or scripts).
All automations created in UI are stored in one yaml file. Imagine 100 automations in one file. Do not think it is easy to navigate between them in one huge file. And honestly see no reason to edit them in yaml.
And my opinion is rather different: all UI-made stuff should be kept in json only.
If you need a reusable code etc - use yaml only.