Do not create duplicate threads.
Closing this one. Everyone can reply on the other: https://forum.pjrc.com/index.php?threads/run-time-non-volatile-read-and-write-to-flash-or-sd-card.77617/
Here is a sixth beta test for Teensyduino 1.60.
This is meant to be a release candidate. My hope is to release 1.60 with
the many small fixes that accumulated since 1.59 before starting major new
development.
Arduino 2.3.x, all systems...