Hi :D
Masking... we tried it years ago and unless EA has improved it a lot, it won't protect the lots from ripping when sculpting.
I remember it well because lot rips were such a hard thing back then and they just didn't go away as easily as they do now.
I find it easier to just delete and undo lots now. It does delete everything from the lots but then I can add them back in EIG- and if it's an update, I've usually redone most of the lots anyway. :)
So, the rips are easier now, RJ. Using the double click or the conform tool *works well- sometimes the lots can sink or raise just like in the game.... :D