A guy doesn't necessarily have to zero deck the block to achieve 0.035" to 0.040" squish. You can juggle head gasket thicknesses to get there. For instance, Chevy makes a shim gasket that is 0.016", so you could have the piston down in the bore 0.024" and still achieve a squish of 0.040" and have 0.024" of deck to take another cut later if need be. There is also a 0.028" gasket from Chevy where you could have a deck of 0.012" and still get the squish where you want it. Even if you do cut the deck at zero and have to cut it again later, just use a thicker gasket to keep the squish at 0.040". I know there is a 0.051" gasket and probably a 0.060" that would allow you to pop the piston out of the bore and still get 0.040" squish.

I hope I'm making sense to you. It's clear to me.