So, I’m having trouble finding an answer to these questions...

I am installing an SFI SBC damper on my 250 and remember reading, somewhere, about machining grooves into it for the V-belt...

Did I read that right?
Does anyone have any details/pictures of this being done?
Does this not compromise the damper?

I have not installed it, yet, so now is the time if I am to modify it.

Cheers!