

There is a class action “mass arbitration” against Google for this:
https://www.classaction.org/nest-thermostat-support-arbitration
Additionally, the Fulu Foundation has a bounty reward out for anyone who is able to get these working with something like Home Assistant.
The pot is currently at $12,856.00 https://bounties.fulu.org/bounties/nest-learning-thermostat-gen-1-2
In the U.S., since doing so would circumvent measures put in place on these devices, publishing how to do this would go against sec. 1201 of the DMCA. This has a risk of a maximum sentence of 3-5 years in a Federal Prison. You can still privately show the Fulu Foundation how it is done, and they will be able to use this information to help their case in their attempt to reform this law.
If you live in the U.S., you can also help by letting your representatives know about this. Here’s an ActionNetwork page that Fulu set up so that you can easily do so: https://actionnetwork.org/letters/right-to-repair-reform-section-1201-of-the-dmca

Thanks, I missed that detail. It’s probably because of the “no class action” clause that this is a “mass arbitration”.
Unfortunately that usually means that Google is paying a specific company to decide on the outcome of the case. in this case it looks like American Arbitration Association has a contract with Google.
They’re supposed to be fair for both sides, but it’s been shown that they almost always rule in favor of the company that has pre-selected them.
If anyone is in this situation, they will likely have a much better chance by convincing a judge to allow a different 3rd party to arbitrate the case.