Hi all,
I've been investigating the use of cirrus-ci for native building of wheels for linux_aarch64. Currently it takes about 2 hours to build a wheel on Github Actions using emulation, but on cirrus-ci it's about 5 minutes. This will enable us to fully test the wheels that are produced, rather than just a subset of tests. It would also be possible to build macosx_arm64 wheels natively rather than a cross compile. Native builds are a huge plus, as it's a lot less complicated when compiling code.

It would also be a possibility to have regular CI on those platforms, which are currently not being tested at all in our CI suite.

Does anyone have comments on the use of yet another CI provider? 

I have a PR open in anticipation of a warm response, https://github.com/scipy/scipy/pull/17029. You can see a build, and the artifacts produced at https://cirrus-ci.com/build/6727646015913984.