[Therion] Build a map with all centerline and partial walls

I am looking at this entry in the Wiki: https://therion.speleo.sk/wiki/tips#showing_centreline_for_parts_of_a_cave_a... My understanding it that this requires making two sets of centerline data, then creating a survey for each set. One of the data sets is for that part of the cave which has walls/scraps and the other is for the remainder of the cave. The thconfig file is set up with only one survey/endsurvey section. I think this also would have to change into two sections. Is this correct? The cave I want to do this for has all centerline data in one big file. It would be a huge pain to separate that into two files. Even more of a pain would be moving the data as sketching is completed. Thanks! -- =============== Bill Gee