Note he says to make the drop bolts long enough to allow the brake pads to be near the top of their adjusting slots as it "gives better braking". That's one answer to another thread you started on this subject.
would you recommend using a recessed nut or standard nut brake for use in a drop bolt?
Back when drop bolts were a little more common, we used to make rear "standard bolt" drop bolts work on the front by drilling out the back of the fork crown and installing a recessed hex nut. It worked well enough.
Since decent quality long reach calipers are easily available, I'd say that you should put the right brake on the bike and not mess around with drop bolts unless you have a real good reason.
Got mudguards to attach? Nut facilitates that, but, drop bold lowers the clearance, because the brake is closer to the tire.
But [+1] with double pivot brakes available in a variety of reach ranges. they are unneeded.