I’ve just started pumping a few weeks ago (10 minutes at moderate pressure) and I have a deep cockhead piercing that transverses from the top of the glans, through the urethra, and out through where a prince albert would exit on the underside. I haven’t had any problems with it.
PAs normally stretch the hole out on the bottom anyway since it’s generally a high-traffic area (lots of pulling and stretching) depending on the gauge (thickness) of jewelery in place.
I don’t see why a piercing should affect a pumper, unless there was some tugging that was uncomfortable with the ring sitting on the bottom. In which case, he could simply remove it for the pump session.