Thanks for the fix.

I think there are still a few things missing.
Atom and volatile are still printed the old way: https://github.com/clojure/clojurescript/blob/master/src/main/cljs/cljs/core.cljs#L9053
As is "undefined", even though undefined is printed as nil because it is catched by the nil? clause:
https://github.com/clojure/clojurescript/blob/master/src/main/cljs/cljs/core.cljs#L8776

Ewen you need to submit a CA if you want to submit patches. Once you've done that you should assign tickets to yourself if you decide to work on them so people are aware of progress.

fixed https://github.com/clojure/clojurescript/commit/34c3b8985ed8197d90f441c46d168c4024a20eb8

patch attached.

I have also made undefined printing to nil.

I hope that helps.