1. To change how the linked_list is ordered will break backwards compatibility for any scripts which rely on order.
Which is why I have stated many times that you should not depend on the order of hash table items.
In the real world, people have relied on this order even if you stated that they should not rely on it in some places (though NOT in the help file). So in the real world this change will break scripts.
Khaled - Upon consideration I would actually go further than I did above and say that there is a pressing need for scripters to be able to store unlimited data in a sequenced list.
If you take away the current implementation whereby -m1 is sequenced, then you will leave mSL without any means of storing large amounts of sequenced data.