I would not drill the steel RAM flywheel. I think it behaves basically the same as the aluminum one that I removed from my Scura.
While the new RAM unit weighs a bit more, the mass is more centralized as it has three spokes, not a full circle. And it only weighs about 1 pound more (not 1 kilo).
Here is a link to a post I made a while back comparing the three clutches:
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