https://bugzilla.redhat.com/show_bug.cgi?id=2263999
--- Comment #7 from Sandro gui1ty@penguinpee.nl --- I think you are correct. The split of pyarrow in smaller sub packages will still require us to drop 32-bit support in pandas since libarrow in Fedora already excludes those.
Regarding koji, I will add a comment to the ticket announcing that we will ExcludeArch a great number of noarch packages. Hopefully there will be a solution to the noarch builds on i686 issue soon.
If not, should we consider the use of ExclusiveArch? That's probably opening another can of worms and might require us to tackle noarch packages that already make use of ExcludeArch.