as an aside in the portion of PEP 611 proposing a limit to the number of classes, the proposal also mentioned reducing the size of the reference count field to achieve part of its object size savings. one of the mechanisms proposed was to implement a "saturating" reference count, though it would be different from conventional saturating arithmetic in that any object that reaches the maximum refcount would become immortal, since we could not trust decref from there to account for all references. something that may be worth considering or testing is: what would the cost, both in performance and interpreter code size, of implementing this logic on every single incref and decref?