Hi,
I'm not a dev, so take this FWIW.
From what I understand Arch Linux ARM has a small fraction of the man-hour and other resources of mainline Arch. Moreover, mainline Arch has the testing repository so software in the released repositories has been through some level of QA. So if mainline Arch is "cutting edge" then ALARM is truly "bleeding edge." It may not be possible for ALARM to have a "testing" repository due to their manpower shortage.
If your group doesn't have time to debug problems like this, passing patches back to ALARM or upstream, the best solution likely is not to purge installed packages from the pacman pkg caches so downgrades are easy. There is also the
Arch Linux ARM Rollback Machine of which you're probably aware.
Just speaking for myself, I greatly appreciate and am much impressed by the Arch Linux ARM project. I hope someday it will be a mainline project parallel to Arch Linux itself
It looks like ARM may be the future.
Clemmitt