'https://github.com/hbiyik/agr'
I started this project for my personal use but it became something bigger and may be usefull for ALARM devs and maintainers as well.
Basically the important part is with this tool you can natively(without a major emulation) cross compile aarch64 or arm7f packages from x86_64 host without really modifying the PKGBUILDs.
I am not sure if this forum is active but i think this seems to be the only feasible way to access ALARM crew.
I hope tool helps others rather than me.. I have documented the general usage and tips in the main README file.