I like to walk through the nodes and preview different states of the stream. Houdini has its own logic to "unflag" the Display Flag. It doesn't jump back to its last position. I customized my own unflagging to the previously flagged node. If you like it, you may use my script (and hotkey it). Or you may customize it to fit your needs, for example always unflag to the last node.

The python function responsible for parameter UI generation is called flag_display () and its code is here.