93-100 much too hot for a hop stand - might as well put them in the boil and cut 20 mins off the brew day. I usually add hops when the temp falls below 80C as the rate of isomerzation is negligible at that point and hop oils aren't vapourized.
Very interesting discovery about clarity. The haze could come from the bittering hops being in the wort for 20 mins extra rather than the average hop stand temp difference of 3.5C, which I doubt would make significant impact.
I get excellent results with hop stands in that temperature range. Hop oils don't exactly vaporize instantly at those temps. I think the vigorous action of the boil has a lot more to do with driving off the hop volatiles at that point. I've done hot hop stands as long as 90 minutes with truckloads of hop flavor (I actually feel that 60-90 minutes gets me significantly more flavor than 30 minutes). A 90 minute addition of hops isn't going to come close to that.
Honestly, it wouldn't surprise me if hop oils are contributing to the haze.
From what i see of big breweries, they go into the whirlpool pretty hot, and go for a good amount of time before they go to the heat exchanger. 100 or 200 barrels stay pretty hot though out the whirlpool.
I have done long whirlpool/stands and thought the results were good for flavor. One can also add more hops towards the end of the whirlpool, as I am dropping into the 180F range. As far as time, you get everything cleaned up and put away, and the fermenters and yeast ready before you chill. So it adds a little but not a lot of time.