You can load ClojureScript :advanced code directly into an ESP32 WROVER for execution upon boot, by creating a binary and flashing it to the JavaScript "boot ROM" area. This has the same effect as when loading code via the Espruino Web IDE, in the "Direct to Flash (execute code at boot)" mode, but flashing is much quicker and more reliable.

Here is a small program that uses enough to pull in data structures, etc, leading to nearly 100 KiB:

src/foo/core.cljs:

(ns foo.core)

(def m {:a 1, :b 2})

(js/print (reduce + (vals m)))

With deps.edn:

{:deps {org.clojure/clojurescript {:mvn/version "1.10.597"}}}

compile this program via

clj -m cljs.main -co '{:process-shim false}' -O advanced -c foo.core

Confirm that Espruino can run the resulting JavaScript by executing

espruino out/main.js

and confirming that it prints 3.

In the above example wc -c out/main.js shows that the file is 96503 bytes.