Stash: Regarding the Adafruit Ultimate GPS hat, it has a built in RTC. I tried setting it up with the information here as a guide for automatic system time, but no luck. Any thoughts?

I think it is probably worth doing the kernel update. This is where i will need some upgrade for dummies instructions.

IMHO Talk to Adafruit - a guess is they only work ( or have only been tested) on Stretch and that Ubuntu handles the serial pins on the RPI differently - hence I say talk to Adafruit.

Or possibly go on Ubuntu Mate forum and see someone there has been successful

Quote from Adafruit pdf "The GPS has a built in real time clock, which can keep track of time even when it power is lost and it doesn't have a fix
yet. It can also help reduce fix times, if you expect to have a flakey power connection (say you're using solar or similar).
To use the RTC, we need to insert a battery." If I have a flakey power connection I wont be getting far with Astro work

Sorry just dont see the point of RTC unless you are using the RPI for something else. The GPS Dongle gives you they date plus Long/Lat (even if you dont use them). Plus the Ublox and other GPS dongles work and have been used by many.

If someone has got the Adafruit Hat to work let hem step forward and help.

You only need the GPS/Time etc when not connected to the Internet else NTP will provide the time.

Sorry if this reply sounds brutal its not meant to be
Having said all that I hope you get it working

The Hat works just fine. I'm really happy with it and I use it for my system time via NTP. However it would be nice if the System can boot with the right time from the RTC right away without waiting for the fix to update it.