I would say, 63, that you have been very lucky. My 35 years experience with 2 stroke, intake driven,diaphram fuel pumps has shown me that they are not designed to move air. Granted, we do not have a substantive, quantitative measurement of how much air is in the line, but I think we can agree that it will not get better, only worse, and with air in the pump, the diaphram will stretch beyond it's designed limits and will begin not delivering the required amount of fuel to keep the carbs full ( a lean condition). This increase in movement will fatigue the material and it will fail. The quality of fuel blended these days also has a detrimental effect on all rubber parts in the fuel system which will hasten their demise.
I would also point out that if that small, plastic bowl vent tube gets clogged or melted shut from engine heat, your air bubbles have no way to exit the carb. They will displace the fuel, dropping the level in the bowl and cause a lean condition. I'm just saying that I would not risk this kind of failure with my equipment. I've seen way too many powerhead meltdowns because of fuel pump failure and at rpms far below 8000.
Gotta love this forum...the exchange of opinions and experience from all angles is unbeatable!