Boost for Reddit has officially died today. It still worked for almost a year after the death of the rest of them if you moderated a subreddit, but now it's actually completely dead.
I think ReVanced patcher has a way to change the API key to one you generate yourself which keeps it working for free as long as you use less than a certain amount of API calls per month, but I think that's going to mark the end of my occasional Reddit use outside of adding "Reddit" to some Google searches.