Since the entire goal of the fediverse is “transporting” all data to all servers inside the ActivityPub/fediverse world, the data of a EU member will be transported all over the place.
It doesn’t work like that, think of your instance being a proxy to the fediverse
Personally I 'd prefer windy over tailwind, also I wonder if there is any significant userbase behind leptos. Infernojs was already a strange choice in that matter, compared to e.g. vuejs.