https://gamerant.com/halo-master-chief-collection-updates-development-done-ended/
It appears they won't be updating the game anymore. M$ called them off because it wasn't making any money. It would be nice if you could update it to work again as a final hurrah but understand you're burnt out from the years you maintained it. I never got a chance to use the tool but it looks awesome!
Hopefully now that updates will be no more, or at the very least few and far between, hopefully someone can make something happen. I was REAAALLLLLY late to the party.