SwnModflowBase methods using full swn rather than limited to the model?

[wkitlasten]

More of an enhancement perhaps: Is the SwnModflowBase class using the full swn object for calculations? For example, is "set_reach_data_from_segments" doing calcs on all of the swn.segments (e.g. line 1050, "segdat = self._swn.pair_segments_frame")? There are about 5,000 reaches in my MF6 model, but it appears calcs are being done on all 300,000 segments in the swn object, unless I am missing something (which is usually the case!).