Stagex - container-native, full-source bootstrapped, and reproducible toolchain to build all the things

Comparison with other distros: https://stagex.tools/about/#comparison

Packages: Browse All Packages | [Stageˣ]

Source code: stagex/stagex: A container-native, full-source bootstrapped, and reproducible toolchain to build all the things - Codeberg.org

Will Fedora use it for their toolchains?

You mean will Fedora use it to build software?
We already have mock to do builds.
How is this an improvement over mock?