Cookie dough between batches - Refrigerate? Or no?
Two hours is on the borderline, so you will have to assess your risk tolerance.

No harm will come to your cookies by refrigerating the dough; in fact, the later trays may actually be superior due to the additional time hydrating the starches.  Baking cold dough will only trivially change the baking time.

I would probably err on the side of caution and put the dough in the refrigerator.

One thing that can speed up your tray recycle time is to cool the tray with running water on the back side, so that you can reuse it right away without waiting for it to cool.

You can also pre-scoop cookies onto a plate, which makes moving them on to the tray much faster.  You can even refrigerate or freeze these pre-scooped cookies.