I like this very much.

Worked in terminal.

But I was not able to capture any useful profiling data when calling ##class(caretdev.zprofile.main).Trace() from within REST API (using postman).

Also "job ##class(caretdev.zprofile.main).Trace("Do ##class(Some.Class).Method()")" does not capture any profiling data.

Is it possible to make it work in those scenarios?

Try to uncheck "Mount Read-Only" in IRISLIB database configuration.

s epochMilisecond=##class(%PosixTime).LogicalToUnixTime(##class(%PosixTime).TimeStampToLogical($zdt($ztimestamp,3,1,3)))*1000