> no popup window to modify anything

The idea is that all the setup is done in the extension preferences. From there, the philosophy is "one click" and nothing else. If you need to fine tune the attributes for each task you add, the official TD extension is perhaps a better option.

> no signs that the task has been added successfully

You may notice that, once the task is added, the extension top-bar icon turns into a ✅ for a couple seconds.

Appreciate the review and feedback!