@mikethompson: Thanks a lot. I was guessing something like that. What I’m doing now is to call [compfn data] and the multifn looks like this and it seams to work.

(defmethod compfn :some-dispatch [data]
   (let [a (atom nil)]
     [(fn [data] …) data]))

Message for re-com users. Try doing this: (set! re-com.box/debug true) That adds coloured borders around all v-box, h-box, gap etc. Can be useful.