Just playing today and thought of this. Don't know if it has already been said before or not but I thought it was a good idea.
I noticed one of my stockpiles was getting too full of rock chunks. It is near my crafting area so i don't need a lot of rock there. Since it is the closest place they can put rock they keep putting it there. Would be nice to be able to set it to like only 20 rock chunks or something like that.
Separate you stockpiles and manage it. Put 2 smaller stockpile, one only for your rocks, and the other for anything else... You can "prioritize" (not sure how to write that word) them normal, high... etc for your stockpiles... So I guess we don't need the number of items also :).
I've already suggested it but no problemz. ^^
Find it if you want to know why just "separating" them isn't fun, dear flesh_god. :P
Or don't, I can tell you: because I make a stockpile for each resource basically, it's a pain making that much, ticking/unticking everything, setting priority, it's a pain in the rear end.
A maximum amount of items a certain stockpile allows would be less time-consuming and just as/even more efficient. ;)