I feel like there has to be an issue in the controller’s firmware. Something makes it not happy and it hangs.
It looks like the important functionality of it keeps working, thankfully (regen did happen when the softener wasn’t reachable via BT proxy or app).
I believe there is as well. My theory is something is causing the connection portion of the Bluetooth code to get in an invalid state and the reboot simply resets the state back to normal. I have this on my list to take a look at and I’ll look at it when I get a chance to. We’re trying to finish up this new product and app that has a deadline at the end of the month, so hopefully I can take a look at this first thing next month. You’re also correct that the valve will still function normally as it only affects the Bluetooth connectivity.
I’ll let you know when I find something of interest.
Did you ever pick up a Bluetooth adapter Tony? Curious to hear whether your if your experience is similar to mine.
I last power cycled my valve on the 25th!
Ahh, I still haven’t gotten around to it! My automation totally took my mind off of it. I’m still averaging 2 power cycles a day. Almost a week strong for you is awesome, though—you’re convincing me to buy one just for the peace of mind 
I’m not so lucky with my proxy - the unit is power cycles ~7 times in 24h on average (maybe it would have even more, but I blocked off 3-5am to prevent regeneration cycle interruption)
I just noticed one peculiar detail. The frequency of power cycling increased tremendously when I got home and my iPhone with Legacy app installed came into range with the unit.
There were only two power cycles between 00:00 and 09:30, but when I got back around 14:55 - a string of power cycles began, followed by 6 more power cycles in 2 hours
That’s right, I had to reverse engineer the password logic, since as you said, I didn’t get much of any info without it.
But as far as functionality goes, even with my old C2.x firmware I can do everything in my own code that the Android app lets me do, which isn’t surprising since that’s what I reverse engineered.
With that said, I’m not sure which features a new board/firmware would grant some of us on older firmware. I can see my flow rate, avg daily consumption, next Regen time, etc. Seems like all the basic features what I’ve had for ~8 have been enough for me at least.
Unfortunately I got pulled away for a much bigger home project and won’t get back to this for at least a couple of months, but will keep you all updated when I get back to it.