Re-releasing with workaround for some calibration glitches - seems to be issue with MicroPython Timers.
With many improvements made to the code, including better calibration and the features of the Rev1 PCB, it's time to bundle up a release. All features are now controlled via the UI Menu, with settings stored at the top of libs/config.py. If you don't have a display you can edit this directly to change settings.
Testing with the stock XTAL shows that it is really only good for short term/testing, as it is too temperature sensitive. I have replaced this with a TCXO on a few boards, and validating/testing those will be the main focus for now.