slow work clsj REPL

Hi! thanks for the work you've done, this is very useful!

But, I met with the incomprehensible behavior of the replays, when I try to set an example in an emacs.
After cider-jack-in-clojurecript - cjs repl work very sow. Just eval (prn "test") - take up to 10 s
I tried run in terminal lein figwheel and then in emacs cider-connect, but i get something like this in emacs repl buffer:

WARNING: CIDER's version (0.16.0-snapshot) does not match cider-nrepl's version (nil). Things will break!
More information.
WARNING: clj-refactor and refactor-nrepl are out of sync.
Their versions are 2.4.0-SNAPSHOT (package: 20171117.317) and n/a, respectively.
You can mute this warning by changing cljr-suppress-middleware-warnings.

And then after run (require '[figwheel-sidecar.repl-api :as ra]) in emacs repl buffer i get in terminal something like this:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by clojure.tools.nrepl.middleware.interruptible_eval$set_line_BANG_ to field java.io.FilterReader.in
WARNING: Please consider reporting this to the maintainers of clojure.tools.nrepl.middleware.interruptible_eval$set_line_BANG_
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

And then repl starts work slow in terminal too.
Any idea what I'm doing wrong?

My project.clj:
`(def shared-compiler-settings '{:main npmdemo.core
:npm-deps {:express "4.16.2"
:ws "3.2.0"}
:install-deps true
:infer-externs true
:target :nodejs})

(defproject npmdemo "0.1.0-SNAPSHOT"
:description ""
:url "http://github.com/lambdaisland/npmdemo"
:license {:name "Mozilla Public License 2.0"
:url "https://www.mozilla.org/en-US/MPL/2.0/"}
:dependencies [[org.clojure/clojure "1.9.0-beta3"]
[org.clojure/clojurescript "1.9.946" :scope "provided"]]

:plugins [[lein-cljsbuild "1.1.7"]]

:jvm-opts ["--add-modules" "java.xml.bind"]

:min-lein-version "2.6.1"

:clean-targets ^{:protect false} [:target-path :compile-path "dev-out" "out"]

:cljsbuild {:builds
[{:id "dev"
:source-paths ["src"]

            :figwheel {:on-jsload "npmdemo.core/reset-app!"}

            :compiler ~(merge
                        {:output-to "npmdemo-dev.js"
                         :output-dir "dev-out"}
                        shared-compiler-settings)}

           {:id "prod"
            :source-paths ["src"]
            :compiler ~(merge
                        {:output-to "npmdemo.js"
                         :output-dir "out"
                         :optimizations :simple
                         :closure-defines '{goog.DEBUG false}
                         :pretty-print false}
                        shared-compiler-settings)}]}

:figwheel {:server-logfile "log/figwheel.log"
:nrepl-port 7000
:server-port 3450}

:profiles {:dev
{:dependencies [[figwheel "0.5.15-SNAPSHOT"]
[figwheel-sidecar "0.5.15-SNAPSHOT"]
[cider/cider-nrepl "0.16.0-SNAPSHOT"]
[com.cemerick/piggieback "0.2.2"]]

          :plugins [[lein-figwheel "0.5.15-SNAPSHOT"]]

          :repl-options {:nrepl-middleware [cemerick.piggieback/wrap-cljs-repl]}}})

`
Cider version 0.16.0snapshot

Emacs 25.3.1

Start with project.clj and reproduce the reported cider-jack-in-clojurescript workflow, including evaluating (prn "test") and requiring figwheel-sidecar.repl-api. Compare the CIDER, cider-nrepl, clj-refactor, Figwheel, and Java warnings; done means identifying the cause of the latency and documenting a concrete compatibility or configuration resolution.