Shoutbox

That was what I asked in the first place

That isn't possible manually.  You can't add someone to the blocked list without first adding them to your account and THEN blocking them, so in effect, creating a new accounts serves as being it's own "Blocked" list....as only the people you add to it will be able to see you.  If one of the contacts you'd wish to block tries to add you, you can just decline the invitation.

As for the allow list, this isn't possible and as I said, it's not possible to export your contacts list anymore.  The easiest way would be to change your screenname on your old account, giving the address of your new account and asking people to add it.....or using the Polygamy feature of Messenger Plus! Live to sign into two accounts at the same time and then add people that way, just going through your contacts list