This just isn’t correct.
It’s all about the cam timing.
If it were an intake lobe that had .100” clearance at TDC, and you advanced the cam 10* it will then have noticeably less v/p clearance.
(Advancing the xe268 cam 10* would eat up .052” clearance with a 1.5 rocker)
And the exhaust clearance would grow.
Thanks for making me engage my brain this morning. Took me a while to picture it all in my mind. I’m thinking if all cams were ground with an ICL at TDC engines would be boring and inefficient at best.