How do the Tumbleweed Folks among us deal with this?

We generally don’t add many third party repos and we set repository priorities. If I understand this correctly, you are currently using official openSUSE packages and your upgrade is prompting you to upgrade them by changing vendor to this home:wolfi repo. If you want to keep the original packages, you just need to set priorities: in YaST 's “Software Repositories” page for instance, you can select a repo and see what its priority is (99 is the lowest priority, 1 is the highest). You could for instance put the official repos at 95 priority and the wolfi repo at 99. This way, packages will remain set on the official repos even if there are new versions on the other repo.

However, if you have packages that you want to get from the wolfi repo but are also in the official repos, with this method you will be asked to change those packages to the official repos, the inverse situation compared to your issue. You can tell the system to keep those packages from your chosen repo, I do it by choosing a version on the YaST Software page.

I agree, all these preferences (currency, time, date, measurements) shouldn’t need to fit in a determined locale box, but if you customize them it’s possible to run into issues. I believe choosing English (Ireland) might solve your issue? Either that or I have found a way to customize it way back and then forgot.