Welcome to the forum.
I don't have any personal experience with Atwood Levelegs. However, I have observed and casually keep track of others complaining about the system.
It sounds like you've done a lot of research already so what I'm offering may be familiar to you so you can disregard. Hopefully others here on the forum who have had personal experience with the system can chime in and give you constructive guidance.
First --again you most likely already have this-- is the specific troubleshooting guide posted on the TiffinRVNetwork site:
Atwood Levelegs System
And have you already contacted
Control Systems Labs? I've heard they were able to diagnose a lot of control board problems for others especially on the Atwood products. In video #2 and #3 below will give you more input on Control Systems Labs.
Take a look at this guy's videos (2lotony aka Fisty's Garage and even though he has a Fleetwood RV) ...it might not be the exact problem you're having but could give you a few pointers:
Atwood levelegs not responding. Help! (Update Links In Description)
Atwood levelegs Not Responding. Update #1
Atwood levelegs Update #2 Problem fixed??
And as you suspect, there are a LOT of others having problems with Levelegs so we can probably dig up more videos, articles, and posts from this and other RV forums as it pertains to procedure to try or suggestions to replace, etc. if nobody else here on the forum has other suggestions.