It's had 1mm taken off which is about 1/2 the outer shell and a tiny amount taken off the face. A couple of NSR owners have commented it's had a lot taken off.
No idea about balancing as I bought it like that, there is a little bit removed which implies it's been done but that could be from before it was lightened.

The weight loss is only about 200 grams (the stock flywheel weighs about 1.1kg), as you say if you remove the inner shell and the magnet you lose far more (but also lose the charge circuit).
All weights from digital bathroom scales with just 1 decimal place measurments so not perfect.

Anyone know what the Tyga HRC copy flywheel plate thing weighs?
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread