Overlays and distritutions

Is there a definitive guide to BBB bit/analog/pwm
that brings together Ubuntu and Debian differences and
makes the the overlay system less daunting?

There are lots of examples out there that are now out of date.
I’ve spent three days going around in circles doing stuff that
I accomplished in minutes on other “platforms”.

This is a good one:
But man, this is a lot to work out to just get at the I/O!