I don't see any good Oracle documents giving JDK end users a description of what the JFR can achieve and giving users an introduction/overview of how to use it.

Can we get plans for a docs refresh in place ?

my search engine returns an outdated JDK 8/commercial article when querying JFR in JDK:

https://docs.oracle.com/javacomponents/jmc-5-4/jfr-runtime-guide/about.htm#JFRUH170