Thanks for the amazingly quick response. Glad both options are possible, as for some games unlimited and external saves are just essential (in my case a tower building game). Going to download this and learn it in and out.
EDIT: Got multiple saves working like a dream. As a test, I easily filled up my SharedObjects folder with two dozen save files. Didn't get it to work on Windows though, but on this PC that seems to be unrelated to this Extension. Maybe better luck on my other rig.