Speed up mcr on Linux using background script

We are writing a web application that runs a deployed matlab function, and returns a result as a json file to be loaded to the web page. (Linux Debian, Matlab 2015a)

It works fine except that it takes a long time for the mcr to unpack for each call to the function. This really slows down the running of the web page.

We've tried the MCR_CACHE_ROOT=/tmp/mcr_cache_root_$USER approach but no success.

We've tried another approach where a small script runs in the background, simply waiting for a user input ( input() command). The idea being that the mcr would remain unpacked while the background function runs. But this doesn't help either - there seems to be duplicate caches.

Anything else we can try?