Theoretically, any interval could exist across the bridge. But one should be careful about moving the bridges to fiddle with this (mine has individual ones, not a single one - especially as I have seen some Chinese ones built).

The bridges most likely may have some reinforcing on the other side of the top sheet of wood - moving them may cause the instrument to be damaged as the stress will then be in a different place from where the instrument was designed to take it.

Fred, the guy who made mine - a triple strung, said there were several tons of pressure on the soundboard.

The fifth difference setup allows some elegant playing techniques.

Robin