Good evening Gary.

1.- With regard to session control you can also implement with htable module (avoiding orphan dialog module).

INVITE transaction

$sht(channels=>$ci) = $avp(s:caller_uuid);

BYE/on_failure transaction

$sht(channels=>$ci) = NULL;

CHANNEL CONTROL ROUTE ->

.

if ( $shtcv(channels=>$avp(s:caller_uuid)) >= "YOUR TOP") ) {

..

Your treatment

2.- My last way is to face dialog module development to achieve your goals, even service restart.

The problem is that dialog module is now continuously changing (dialog, dialog_ng, . ) and you'll have to accomplish your development with new changes.

Regards.