@Sobex @SharpLimefox For TSO they fear "fragmentation" as in developers using TSO to work around arm64 porting issues instead of fixing the code, even though there is no evidence of anyone ever even thinking to do that.

For cpuidle, the maintainers want PSCI (a firmware interface) to be the only cpuidle driver to avoid driver proliferation. Unfortunately the PSCI spec was written with assumptions about the platform that make it impossible to implement on Apple Silicon despite it being a conformant arm64 implementation (they require optional features).