https://reactjs.org/docs/dom-elements.html#dangerouslysetinnerhtml As the name says, this is dangerous

The above works only if you save HTML as a string. For Hiccup, you can serialize it as EDN or Transit before storing and deserialize upon retrieving so you get a proper Hiccup vector and not a string.

Also note that you won't be able to make that Hiccup use any CLJS code without hassle. I.e. in plain code you can write stuff like [:button {:on-click #(...)} "Submit"], but it won't get serialized properly. Best you can do is [:button {:id :submit} "Submit"] and then attach the onClick handler dynamically. Given that, I'd reconsider the whole approach. If it's possible, it would be much better to have a registry of possible elements and their settings and then use IDs or whatever from that registry when storing the current configuration in the DB.

Ok, thanks. It's not, what I hoped for, but ok, Rethinking most of the time is a good thing though...