Here's a excerpt from the stroker small block book with a twist.
They recommend a hole in the plug but not for the chain, but for the fuel pump eccentric.
I have that book and I read that. I leave the plugs out (evidently a mortal sin condemning me to an eternal hell) and just drill a .040ish hole in the plate. I've used gear drives forever. Never ever replaced a bearing or a gear. And that's running springs with 340 on the seat and 900 plus over the nose. In my TC&G stuff you see almost no chain wear.
And yes, I run a gear drive and a mechanical fuel pump.
