I’m using Flarum now for my personal blog too. With a couple CSS tweaks it looks like any minimal blog. But better. But, since it is a personal blog I don’t expect that people will sign up. I don’t care too much about guest comments. But, it would be nice if people could at least like posts without signing up. And so, my suggestion is to one day add a setting to the core likes extension to allow public likes. They can be stored with a cookie and/or IP address.