Hi all, "withsmalldicts" is not enabled by default, I suppose because we measured that it didn't help. However I've found a bug which I think means that even when the option is enabled, they won't be used in most common cases. The bug is that the option is checked in EmptyDictImplementation.setitem() but not in EmptyDictImplementation.setitem_str(): the latter always creates a non-small StrDictImplementation. Anyone feels like fixing and re-measuring this? Armin