How to keep cache files after plugin update?

Ok, after having digged into WP source for a couple of hours, found a workaround. Simply tell wordpress to NOT remove old files.
Now files are 100% overwritten and cached files maintained.

Code is really simple

add_filter('upgrader_package_options', 'avoid_deletion', 999);
function avoid_deletion($options) {
    if($options['hook_extra']['plugin'] == 'my-plugin/my-plugin.php') {
        $options["clear_destination"] = false;
        $options["abort_if_destination_exists"] = false;
    }

    return $options;
}

I will write lately an optional method to remove single folders/files just in case.