What's been built and verified, separate from the documented target design.
macOS has been the project's own development and verification platform throughout building the protection pipeline, including end-to-end runs against an unmodified 1,200-plus-class third-party application.
The project's own build-target design specifies a tiered platform matrix, modelled on a comparable native-compilation tool's verified split: stable: Linux x86-64, Windows x86-64, Windows ARM64, and Apple Silicon macOS; experimental: Linux ARM64 and Intel macOS. This is the documented design, not a claim that every listed platform has been built and tested. Cross-platform builds have not yet been independently produced outside the primary development machine.