In the plane cut option in Dynamic Modeler module, I found that if two models are chosen in the output nodes simultaneously, the number of points is identical between the two output models when inspected (Slicer 5.2.2 on Windows). The models show a difference in surface area, volume, and number of cells but not number of points. In the 3D view they also look fine.
If, instead, the same result is achieved in a two-step process (i.e. leaving one of the output models as None for one of the positive and negative components), the new models have different number of points, similar to the other model properties.
I’m later calculating thickness from the cut pieces, and the identical number of points becomes problematic with the simultaneous option. The second way is a workaround but just reporting in case this is a bug.