I'm not sure if it's feasible or useful doing here, you can register a url mime type in ur UI's .desktop file. Then you could pass that url mime in feeditem's urls. Doing that would invoke your UI automatically whenever items are clicked, along with the url as argument to ur exec specified in that desktop file

And probably you need to separate your UI and daemon. Daemon should be running in back, UI should open and close but not access backend tasks as long as daemon is running.

Not sure if there is an way to synchronise the resources loaded by daemon to make UI startup faster (was it booster's purpose?) , but I think I read it somewhere.