Kosta tawk widget uses absolute positioning so you don't even need a menu item or css for their widget.
If you put a reverse proxy in front of control panel like let's say NGINX or a python script, you can inject their script. Enhance updates won't affect it. You give customers the reverse proxy url.
My script should be stable though and even a basic bash script can make a backup of index.html and inject the code into index.html. After an update check the selectors and update if needed.
I don't think enhance is going to add these features in the near future.
