Yesterday I learned something new about boosting on #Mastodon: if you boost the first message of a thread, then it isn't necessarily true that all your followers can click on it to see the entire thread. Replies aren't fetched by remote instances. If you need the last message of a thread, then all its ancestors will get fetched by remote instances. Your followers might still not see all the threads that branched off of the original, but they will see at least the one thread.
@kensanata I think this is currently the biggest shortcoming #Mastodon (#fediverse in general?) has. Mostly just the original poster sees the whole #thread. It creates a lot of duplicate comments etc. I'd prefer if the client would automatically fetch it for me when I expand the post.
It's why I open most posts via permalinks to see the whole threads from the source server. Being on a #single-user #instance, most posts I see have zero comments even after subscribing to all relays I've found.