I think your response is inaccurate in many ways.
A wheel can be out of true side to side and still be balanced. I do vertical trueness first, then do side to side. The vertical trueness is the one you feel to be out of whack at over 25mph. Forget the pencil and tape, or the c-clamp brake, just use a zip tie on the fork or seatstay.
You also forgot the part on stress relieving new spokes before use. Do your research before pretending to be a pro! The people who read stuff here ride at non trivial speeds and giving advice to build an improperly built or repaired wheel could result in a major catastrophe.
And yeah, welcome to the forum, a place where anybody can give their opinion on any topic they please....