Hi Wild Bill
Mike Walker here I make the Harman Titan pinhole cameras, acid etched holes are superior to laser holes, and if done the right way they very very round, I am going to upset some here, put round does not matter that much, it is more the sharpness of the inside edge of the hole.
I can back this up, as Schneider once had a play with this, and by taking 3 scalpel blades interlocking they and blacking with candle smoke made what they said, was as sharp a pinhole as it was possible to make.
Hope this helps.
Mike