I agree that native script function calls won't be notified. However, getting notified of all host method/property invocation in a single place where we can also get the script line index would be useful. With this we will be able to tell the user the line that is getting executed. This will not give clear progress info in terms of 'how much is done and still to go'. But then in case of loops and branches it would anyway be a challenge to give extent complete. So, I guess, interception with line index would be a good start.
Regards,
Ram
Regards,
Ram