Self-Hosting Lemmy: How easy is it to federate?

I'm considering running my own Lemmy instance just for myself and maybe a few friends, but before I go to the trouble I want to make sure I don't get into a place where I've put the instance up but no one will federate with me because I'm too small to be worth it and they're overwhelmed by federation requests.

Those of you who've set up an instance, was this a problem? Do the big servers have explicit allowlists, or do they tend to blocklist instead?