Due to the fact that both segmentation views use the same toolmanager instance, we run into inconstencies invalid states if both views are opened in a workbench session.
We have a kind of race condition, because both views set the reference image and work image of the toolmanager due to various events (from node change to rendering reinit). And the views also use the toolmanager data as a kind of internal state because the continiuosly use it like there own member variable. This leads sooner then later to invalid states, strange view behavior or crashes.
Seperating it or making it lokal is not trival and basically leads to a complete overhaul of the segmentation (which would not the worest).
The most sensible but pragmatic mitigation strategy would be to prevent that both plugins are not part of the same package. Either be documentation (weak) or by adding a check on the CMake level preventing that both plugins can be activated at the same time.