Are you trying to solve a technica, or political/moral problem? Let’s Encrypt doesn’t create, see, store or log your private cerficates. So, even if they are in the US, I don’t see a risk, and otherwise, the other parts you use in general are probably vulnerable to the problem even if non-US.

For ex. the US could simply order browsers stop validating any certificates not issues by US companies in browsers. And whoosh. Having a non-US certificate won’t help much there either.

It’s not bitching if it’s true. Nextcloud has really poor performance alone, it tries to do to many things at once and none of it ends up being good. It was amazing for it’s time and it’s idea but it simply doesn’t scale, not technically, not with time. They need to redo the architecture and probably move to something better performing than PHP. I never heard anyone in any environment even considering PHP as an option in 2025.