It’s not particularly sensitive, for example mine ran after a Fatal backup result code logged by
echo %DUPLICATI__PARSED_RESULT% > “%LOCAL%\result.log”
There are surely problems that might cause it to not run, such as an app crash or system down.
If systems are supposed to stay up, and on a schedule, some monitors alert on missing reports.
“Duplicati Monitoring” is old third-party one, and Duplicati team has been developing something.