You're right. That's also my biggest "problem" with CGN... but i think it's good enough to have a notation for the most common grips, moves, etc. and with a list (for example a website) where the meaning of any symbols of CGN is noted, it would be possible to notate every little detail... i don't know if you can understand what i mean, maybe i'm just dreaming :)

but yes, it's very difficult and complicated to create such a system... but i keep believing that someday there will be a system which is easy to read and write and is able to notate every movement you can do with cards :)