Basically, what I think Tony means, and what I thinkas well is:

You are over complicating this by a long shot. By putting it in the DP you'll have to add numbers up on the fly to get your reading, and even if you are worried about the gauge pegging and reading only 1600 when its actually 1700+, it doesn't matter. If you are running 1600 at all you are near a danger area so you should have it tuned better anyway. All it seems like you are doing is adding an unnecessary step. Also, when you start modding it heavily it will be a HUGE pain in the butt to look at a few gauges and then for one of them have to add numbers on to it to make sure that reading is within safe specs. Or just buy a gauge that reads higher than 1600.

Looking from boost to EGT to knock to SAFC is tough. I melted a piston with Jeff in the car helping me monitor and neither of us saw the EGT's climb to danger levels. We were looking at other things. Imagine having just you in the car and then having to look at EGT, see where it is, then add a number to that to see if you're in spec. It just seems so overly complicated. You get the most meaningful and accurate readings in the exhaust manifold, so why do it anywhere but there. If you are worried about tapping and drilling it and it breaking off, have a shop do it for 10 bucks. Professionally done with no worries and you can check the probe every few months or so to see if its intact. It just unscrews like a normal bolt.