I see I made my first post on this issue over 3 years ago. After having successful heater operation all winter this season I believe I can finally say my initial issue (which started this thread) has been resolved. The solution was fortunately/unfortunately to replace my easystart timer (EST) heater controller with a new controller. This time, I ordered just the regular easystart controller from heatso.com
, mostly because I never really used the timer feature and just didn't want to pay extra. Wired it up, just like I had the old EST, to the heater and high altitude kit, and that was that. Has consistently worked with no hiccups (knock on wood) over multiple cold weather trips all season long. Years of fiddling solved by about $60 and 20 minutes of (re)wiring work.
So that makes 2 of us with similar symptoms that ultimately ended up being a bad EST controller unit (Midwest drifter posted on the same solution back in Nov 2017 - I am just a little slow to act). Hopefully this helps others who have similar issues and have exhausted all other troubleshooting/wiring options. Thanks to all that helped me through this.