Today the 'jfr configure' command prints the following:

Options for default.jfc:

  gc=<off|normal|detailed|high|all>

  allocation-profiling=<off|low|medium|high|maximum>

  compiler=<off|normal|detailed|all>

  method-profiling=<off|normal|high|max>

  thread-dump=<off|once|60s|10s|1s>

  exceptions=<off|errors|all>

  memory-leaks=<off|types|stack-traces|gc-roots>

  locking-threshold=<timespan>

  file-threshold=<timespan>

  socket-threshold=<timespan>

  class-loading=<true|false>

There is no default values, which makes it harder for users to know what a reasonable value could be.