hardwood bullnose install technique

I am installing hardwood flooring with tounge and groove connecting the slats.
For the T connectors I built a tack bar with 1/2" 19ga zinc nails as tack every 6 inches. Small enough not to crack/split the hardwood and yet enough to hold the T's in place. If they have to be removed the tack bar or 1/8 hardboard will rip and can be easily replaced.
Now I have made the nail holes disapear for the T's I want to do the same for my Bull nose. Note this is on a living room "stair" i.e. a 13 foot length 2 pieces of noseing. I think the stresses will be quite different here.

Any Ideas how to install the nosing without and nail holes (even filled).

Hardwood is bamboo (horozontal) tounge and groove. Nailed down (not floating) .

thanks /drj