Outgoing calls minute reminder

I'd like to have this feature on outgoing calls:
- first vibrate (or beep) after 45 seconds call answered;

- then vibrate (or beep) after every other minute (1.45, 2.45, 3.45 ...)

I created this task in Tasker:

1. wait 45 seconds;

2. vibrate time 50;

3. wait 1 minute;

4. goto action 2;

and put in context: call outgoing.

It kinda works but has a few shortcomings:

- timer starts just after phone number is dialed, not when call answered;

- task keeps going on after call is terminated, need to manually stop it.

I tried with an exit task with an explicit stop action but did not work.

I read about AutoNotification plugin intercept feature but did not understand.