>I assume that restoring the backup will preserve the ones that are >currently there, am I correct? What do you mean by "currently there"? If you're talking about aliases that were in the user account already, with the limited amount of space, then yes, those will be preserved across an upgrade.
If you're talking about the old style aliases that were in the vCard and got cut off during the phaseout of vCard-borne aliases, they will continue to be cut off at the same length.
