Your lst files change often without the extensions themselves changing? That's a really specific setup. Normally you'd imagine updates happening at the same time.
The static_ip patch is probably not used by anyone else either, but the lst one just makes no logical sense. As per the script, the lst files are supposed to be right next to the extensions, same media, same partition. For them to come from a different device altogether makes no sense. So I'll ask you to keep this one as a local patch.
Using an iso this way with many VMs may be more convenient than a shared NFS repo, I acknowledge that.