I'll mirror what @Bobby_M said. I would definitely be worried about tannin extraction at those temps. Regardless of what the temperature of the wort is coming out, the temp at the top is 195 F, which is well into tannin extraction territory.
As was also said, you're basically doing a mash out, but you're risking tannin extraction. If you're going to be adding near-boiling water anyhow, why not just do a mash out and get your grain bed to 160-170, and then just sparge with that temp sparge water. You'll end up with wort coming out in the same temp range, but without the risk of tannin extraction from continuous exposure of the grain at the top to hot water temps.