I don't think this would work. I mentioned above that potterworld runs best on 1.12.2 and I believe when it was first available for pw, people were having glitchy resource packs and I think there was some issue with swimming - I'm not sure if these are still the case though. In the future when these issues are ironed out, it's possible that potterworld will be able to remove the older versions, but it will probably take a while, and I think they would prioritise being able to use newer versions.