The veneer pins are. Very thin. Less than a mm. They leave a neat hole. I put the holes in an even row so they look neat.

I don't use a packing piece, if you use the heat gun to give the appropriate twist where necessary you don't need massive holding force. The friction on the shaft of the pin is enough. I only tap them in half way. They are just to hold the strip against the previous strip at the former. The tape or rubber between forms does the rest.

Of course, if your rolling bevel on the strip is not accurate, or not present at all, you will pull the strip out of alignment between the forms with the tape. Then, maybe, staples are useful between formers.

If I was using unbeveld strips for a rush job though, I would probably just tape the inside of the hull to align strips and Maybe a drop of hot glue here and there for recalcitrant spots.

Not using the heat gun is the major factor in needing holding power, in my experience.

Et.