I haven't had any clutches yet, but I've read the same stuff as you. But after thinking about it and reading about how others do it the ONLY reason to cut early is to see what you've got. But even then, with a lot of morphs you might not be able to tell from a little cut in the egg (pied with low white and the white is underneath, etc) and sometimes you need to wait for their first shed to really be sure. So all you're cutting early for is a chance to see what morphs you got.
I understand the wait though, trust me. My gf and I are breeding chameleons too and we've been incubating eggs for almost 8 months now and they might not come out for another 4 (or even longer).