I got reindexing working mostly fine, with a live progress bar and actually in the background. So v0.5 should have everything this plugin needs now.
I'll still look into a possibly better frontend integration with their libraries, but I'd probably need to replace the existing NodeBB search preview. There is also a bit more sorting/filtering I want to pass to Meilisearch instead of leaving it to NodeBB later, but that's not a big deal.
I'm also considering if some LRU cache for recent searches is needed, but I'll have to test performance on a larger instance than my tiny tests 🙂 I'll probably end up adding one with low TTL though.
So since it's close to release-ready I created a topic for it: https://community.nodebb.org/topic/16658/nodebb-plugin-meilisearch-use-meilisearch-as-a-full-text-search-backend