Not sure about standard, maybe quite common among tour players who are provided half a dozen tour issue heads to play with. I thought hotmelt was a highly sophiscated, near-irreversable custom job for players with very specific needs, not a “standard†step during the manufacturing process. I guess this is why the retail heads come with the port plugged and the tour issues with the port left open.
What really rattled me was this question, how would consumers like me know if there is hotmelt inside their $500 brand-new driver, not to mention where and how much exactly? You can only assume it would be anywhere near the hotmelt port, if any, as you can see in the article. I see some poor (very minor but still poor) paint jobs on about 2 out of 10 drivers. I cannot even imagine what kinda hotmelt jobs out there inside those heads...