Tracker-4.5.4 has been released as the official/stable version and can be installed using MP, QGC or the firmware can be directly downloaded from firmware.ardupilot.org.
The single change vs 4.5.3 is listed in the ReleaseNotes and copied below
- Disable highres IMU sampling on ICM42670 fixing an issue on some versions of Pixhawk6X
If you’re using a Pixhawk6X we strongly recommend updating but for other users this release will have no impact.
By the way, some may notice that we released this version without going through the regular beta testing procedure. We decided that this change was small enough that developer level testing was sufficient.
Thanks!