At the time this was re-added, there was concern around how the JIT
would handle the system property that enabled it.
This shouldn't be a problem, and as such we no longer need to block
access to it.
The Vanilla Method Profiler will not provide much to most users however
there is no harm in providing it as an option. For most users, the
recommended and supported method for determining performance issues with
Paper will continue to be Timings.
When enabled, Parrots will not fly off of a player's shoulder everytime
they change Y level, touch water, sneeze, etc.
Instead, a player must toggle shift to "shake" the parrots off.
