Chris,
Show files are version specific and not backwards compatible. Meaning if you start a file on 4.2.1057, you can open and edit it on 4.3.1183, but after you save it, you won’t be able to take it back to 1057. Your only option is to upgrade your home machine or downgrade you work machine.
I would actually advise updating the home machine. I understand the Enttec issue, but you’d probably be better off upgrading and purchasing an NX DMX for around $300 (or less).
My reason is that I have 5 volunteers who all use the same version as the actual console and they all prepare from home. With certain windows updates and security (in the past) the only way to fix them was to upgrade to the current version. While you can try to stay at 1057 (and use enttec) as long as possible, at some point for security you may have to upgrade.
Hope this helps,
Watson