'Little thing' 
For the outer top and bottom ones all horizontal angles are correct, so the only way to get a perfect textured sphere you have to take into account the other points of the triangle/quad you're working on (creating multiple vertices for the same top/bottom xyz).
The same problem with -180/180 coordinates. Don't you have this problem at the backside of the sphere/cylinder?
On the other hand I'm wondering if the spec was ment to be used on enclosed objects, it being projection orientated and all.
I'm also curious... how does it look when you map a texture on something when the outer edges of the texture don't align with ldraw points? e.g. a -60..60 deg on a 16 facet cylinder (texture should starts and end in the ~middle of a segment?)
For the outer top and bottom ones all horizontal angles are correct, so the only way to get a perfect textured sphere you have to take into account the other points of the triangle/quad you're working on (creating multiple vertices for the same top/bottom xyz).
The same problem with -180/180 coordinates. Don't you have this problem at the backside of the sphere/cylinder?
On the other hand I'm wondering if the spec was ment to be used on enclosed objects, it being projection orientated and all.
I'm also curious... how does it look when you map a texture on something when the outer edges of the texture don't align with ldraw points? e.g. a -60..60 deg on a 16 facet cylinder (texture should starts and end in the ~middle of a segment?)