Currently, the v2_cart_model code processes erbs by calling @container.run_in_container_context once for each file to be processed.  For a cartridge with many environment variables or configuration files written as erb files, this can consume a considerable amount of time.  each call results in a runuser->runcon->sh->scl->ruby process tree, and calling runuser many times can really bog down a system due to pam_namespace, cgroup switching, etc.  Perhaps we could create a simple script that can process a whole list of erb files in a directory?