> there are people who want to avoid distributions made by Russians

Well, racism / citizenship-based discrimination is a thing, yes.

> Are builds reproducible?

A valid question, but what does that have to do with the ethnic background or citizenship of the distro makers?

> Where do these people reside?

It seems their team is from all sorts of places, although it doesn't exactly say where in the world each of them is located:

https://cachyos.org/about/