Since Joint Push Pull is a third-party plugin developed by Fredo6 and not a native feature of SketchUp, the "features" refer to the specific tools and capabilities this extension adds to SketchUp 2021.
Normal Push Pull (N): Pushes each face along its own individual normal. Unlike the Joint version, this will usually result in the faces "splitting" apart if they aren't parallel. Joint Push Pull Sketchup 2021
Cause: JPP creates temporary geometry. If your mesh has >50,000 faces, the undo buffer chokes. Fix: Since Joint Push Pull is a third-party plugin
Round Push Pull: Extrudes and automatically rounds the resulting edges, with adjustable segments for smoothness. Essential Installation Requirements Joint Push Pull Sketchup 2021