Just some thoughts about the experience I got with Pool in old VW.
I think that the problem with Pools is that they are static. (I did not checked in Squeak) but in VW pool have to be defined before the method that make references to them. To that regards Pools are not equal to class methods of a class that would represent the Pool.
So I always thought that Pools were kind of ad-hoc.
I do not know what you think about that but I have the impression that Pools were an optimization rather than something really needed.
In the new VW5, I understood that the semantics of Pool is more dynamic which raises issues of concurrent synchronization. (I cannot tell more because I never look carefully at it).
Stef