p5p summary: Improving threads::shared ?

(Apologies for not tracking p5p closely, I just
don't have time these days)

I've been pouring over the p5p archives trying to find
what the subject p5p summary item is about, but wo/ any luck.
Can someone point out the relevent thread title, or maybe
summarize what "threads::shared could share aggregates
properly with only Perl level changes to shared.pm"
means ?

TIA,
Dean Arnold