Looking into this deeper, shadow-cljs doesn't support it out of the box. Attempting to use it with preact-cli just makes local dev slow I've not looked too deep into the internals of shadow-cljs: how hard would it be to add support? I assume there's some sort of check for react to inject react-fast-refresh so I should just implement the same and shoot over a pr?

you can check #helix 's fast refresh impl

Duh, should've checked there first. Seems easy enough to translate to Preact. Thanks!