Fisheyes don't appear until you apply the topcoats or have filled the grain completely. That's why they always seem to be in the topcoat. The shop has an excellent reputation for cleanliness in their spray area, because of all the white enamel they do. They are also very aware of how silicone problems happen, so I was surprised that the problem was occurring here. Shops that spray a lot of enamel doors are often considered the better educated finishers in the market.
Silicone is the worst offender, because it stays airborne in minute particles.
It floats around the shop landing on wood, tools, and equipment. After eliminating the most likely causes of the problem, I visited the shop for a fisheye hunt. No fisheyes appeared after dusting the raw board. If they had, I would have known that the board coming into the shop was contaminated from the board supplier. It is not uncommon for board mills to use tool lubricants that transfer from the cutting tool to the wood.