Hi Grant,

Thank you for reporting the issue.

The deprecated API "avmd uuid stop" call can still be used, though it is advised to switch to new APP "avmd_stop", when called from scripts.
There was a bug in "avmd stop". This has now been fixed: https://freeswitch.org/jira/projects/FS/issues/FS-11708

What is the performance impact if we leave out the avmd stop command? Will any resources consumed by the module be cleaned up automatically after the call disconnects?

Avmd will be processing incoming audio. It won't consume resources if audio is not written to FS session.
Avmd threads will be sleeping. All resources will be cleaned up when FS cleans up session of that call.

I have plans to create improved avmd, using different algorithm for tone detection.
Everyone is welcome to add to requirements, so we can make it better:

cheers,
Piotr