I am not one of those that will just nod in agreement when I don't have a clue what you are talking about so this may come across as a stupid question.
So much of what we measure is at mean chord. For whatever reason I have always balanced my planes at that point. Seems silly since balancing them at the fuselage is just as easy. Maybe it is so that I can get a quick visual on where my wheels are relative to the balanced point. So, when we just say 2 1/2" behind the LE, where on the LE is that? Centerline, fuselage joint, mean chord? I know, it is on the plans but the only plans I use are ones I drew up and "That looks about right" is not a standard linear measurement.
I just make sure the CG is behind the wheel, tape one of those little line bubbles to the nose and hang it till I get a slight down bubble then go out and fly a couple of 15 seconds flights. To me on a first flight it is only important that the leadouts be behind the CG, the wheels in front and that there are the same number of takeoffs and landings. I find bench trimming for balance to be a waste of time. Getting the right tip weight, CG and leadout position are best done at the field.
OK, this is the point where you call me an idiot ....
Ken