By the way, I've been asked multiple times how toots are actually sent between instances.
It's one of the best kept secrets of the fediverse.
You probably heard the word "Sidekiq" before: when a toot comes out of its conception chamber, Sidekiq workers have the task to kick them hard enough to propel them to their recipients instance.
If the toot goes too slow, the encryption will be weak, or worst it could fall into the dark web. Too fast, and it could reach another instance.