How do I move up in rings? I've been in Omega for months

One thing to be aware of, you must be active in the insider program for a while, and be selected for the alpha ring. You will likely start in the "Omega" ring, and after 1 month you can move up to the "Delta" ring. 3 months will get you
into the "Beta" ring, etc.

I think it may be fixed finally. I just downloaded an update on the Beta ring as an Xbox insider and played crash free over multiple turns. This was on a game I've been trying to finish over 2 months now, that was crashing multiple times per turn.

This is in Beta ring. How long does it take to go GA from Beta? I assume it needs to pass Delta and Omega first? Another 3-6 months?

It looks like it hasn't been released for the Omega ring yet. Hopefully soon!

My console was on the Beta ring. I moved it to the omega ring, essentially rolling back several updates. After xbox was setup again, the issue still persisted. I log on today after work apx 16 hours later and normal upload speeds were back .

In my understanding the Dashboard experiment, A, B, C selection, is totally random.

As "Both consoles say their OS Version is (19h1_release_xbox_dev_1911.191028-1335)" your consoles are either in the Beta or Delta ring.

Both those rings and Omega ring are getting a preview update News release notes Beta Delta Omega
Insiders today, which you can manually start or wait until it becomes mandatory.

After you do the update, if you want to change rings, it will be the perfect time to change as all those rings will be on the same release. Subject to eligibility.