That is the gist of it, but it requires a few tricks like JSON conversion, possibly column autocast or type conversion on the child side (+ looping for multiple reports). The JSON conversion can be seen in the @ipazin solution. All credit goes to the great Ipazin!
I also had a few tricks on this thread that I use to avoid errors and simplify version changes / testing in the child workflow report generator. Things like passing through the same JSON conversion before report building in the parent workflow, copy & paste techniques, creating a test data file to use within child workflow, etc.