We're working on a game that will have procedurally generated levels. One of the approaches to level construction we're considering is using big tiles like those used in Diablo 3

Tiles in Diablo 3 seem to use some form of lightmapping (at least the ambient occlusion is clearly visible). The game reportedly runs well on low-end PCs (with dynamic shadows turned on), so it's unlikely that it does lighting in realtime.

The question is, can Unity / Beast lightmapping be used with big-tile levels, and how?