I tried to run:

$ java -XX:StartFlightRecording ...
$ jcmd <pid> JFR.dump filename=test.jfr path-to-gc-roots=true

on the latest JDK 13 (debug-level=release) with a heap of 150 MB and it took 5 seconds. This seems at least a magnitude too slow This was done using an application that fills a HashSet with objects (shallow heap). This could possibly be a regression from "JDK-8214542: JFR: Old Object Sample event slow on a deep heap in debug build"