You want to be careful with this technique when payload size dominates your application's performance, like on a webpage. I was looking into improving Emscripten's pre-execution behavior, but found that ended up making perf worse when factoring in standard download speeds. The functions it removes are usually smaller than the data they add, usually with worse entropy. So while JS is faster to execute, it's usually not faster than the transfer time.

It gets a bit worse if your initialization code is doing a lot of dynamic allocation, as you're shipping