Better wait until it's federated, because it'll likely change a lot in meantime. Why bother getting used to an unstable WIP with uncertain future?

It was important to get in early on Twitter, it was centralized so people wanted to squat usernames, but Bluesky is decentralized so that's not a thing. I bet most people who beg for Bluesky invites just resell them, as accounts are otherwise completely worthless as soon as beta is over and federation rolls out.