Proper length spoke comes right up to the slot in the head of the spoke nipple..
now if you have a longer axle on the left side + dropout spread..
so as the hub shell re-centers itself flanges equally distant from the center line ,
then you can have equal length, and balanced tension ..
Then again , that is part of the durability Of Internal gear hubs and single speed hub wheels ..
I think Phil Wood made some rear hubs larger left flange to use same spoke length
for both sides of rear and the 2 on the front.
then again, ''//,,
My wheel build on a [limited production] Campag Hi/Lo rear hub accentuated the differences , laced the small flange left with a 4 cross pattern
High flange right is a 3 cross, still holds it's true 20 years later..
JRA