A replay of a flight in the app does show the RTH height at take off, as a message. At a guess any subsequent changes made during that flight might also show up as a message but I don't have a charged phone with flights on it at the moment.
That said that is not necessarily the current setting.
RTH height is recorded in the app so you can view it in the csv of a log but again the value shown in the last log is not necessarily the current setting.
Why do you ask?