[Therion] An extended elevation problem

Hello guys, I have a problem with a cave on which I would like to have a partial extended elevation. The cave is small, but the centerline has a loop, and when I compole an extended elevation, even with half of the loop flagged with a "extend ignore", Therion thinks that the stations in my extended view are very far, as if it did extend using another branch of the loop... Is there a trick to do a partial extended map ? (well, may be I could do an elevation instead, but this is not what I wanted from the beginning...) How could I do several extended maps for different parts ? Eric.