Specter has been updated for bootstrap ClojureScript and can be used with Planck. Here's how:
First, make a Project file
(defproject sp "0.1.0"
:dependencies [[com.rpl/specter "0.10.0"]])
Now you can try Specter constructs in bootstrap ClojureScript!
$ planck -qc `lein classpath`
Retrieving com/rpl/specter/0.10.0/specter-0.10.0.pom from clojars
Retrieving com/rpl/specter/0.10.0/specter-0.10.0.jar from clojars
cljs.user=> (require '[com.rpl.specter :refer [transform ALL]])
nil
cljs.user=> (transform [ALL :a even?]
inc
[{:a 1} {:a 2} {:a 4} {:a 3}])
[{:a 1} {:a 3} {:a 5} {:a 3}]