I also put a small piece of tape over the pump chuck to keep dirt and dust out of the chuck. I do not want any dirt to get into the valve on the inner tube where it might result in a slow leak, etc.

The two bikes where you have the pump in the top tube, the pump should stay cleaner there. I usually use the seat tube mounting point and I get a lot of dust and dirt there from gravel trails. I occasionally have to take a pump apart to clean out a lot of that excess dust. I get more dust inside my Road Morph G than I do on my Lezyne pumps. I think the downtube mounting results in the most dirt and dust on the pump.