I've found some problems with the hooks/use-component function in the fulcro-3.5 branch. Firstly, the initialize? option is given the default binding of true with associative destructuring, but this binding is never used. Instead, the original options map is passed directly to rapp/add-component!, so initialisation of state does not happen by default. I assume it is actually meant to be true by default either in use-component or add-component!. Secondly, the initial-params option is completely ignored for the first comp/get-initial-state call because (or {} initial-params) always evaluates to {}. I believe the or should be omitted, since a default binding has already been specified.