I’ve been experimenting with mash temperatures quite a bit lately, and have seen the difference in attenuation between brews mashed at 154, 152, and 150 degrees. Now I’m wondering, if one sets the mash temperature relatively high, say 154 degrees, and let’s the mash continue for whatever time it takes to cool and sit for an hour or so at 150 degrees, will the result be as fermentable as a straight 150 degree mash?
At the higher temps (which favor the alpha amylase) you start to denature the beta amylase which favors the lower temps.
So the end result will be somewhat different.
Fred
I’ve often wondered what the difference would be myself. Keep us posted if you do a test.
I don’t know if this makes a difference in regard to the OP’s question or not but I’ve been experimenting a little in that area, only because the first batch I had a helluva time getting the mash temp up. 
First one was as I said, my mash temp was too low and I ended up having to add a lot of water to get it up to temp (wow, Michigan weather is teaching me just how different 400 miles north is when mashing!) Anyway… the batch ended up over-attenuated imo and I’m going to dump it. I had pitched one packet of S05 (11.5 grams-dry) onto wort cooled to 56 degrees. It carbed Fast in the keg and I taste phenols… yuck!
Next batch I hit my mash temp but decided to try an overnight mash and the mash cooled to about ~101 degrees . I read what Blatz posted about one of his buddie’s having problems with it over-attenuation when overnight mashing… I’ll check the gravity today or tonight and see how it faired but I’m betting Blatz is right. Thinking it might do that I added half a pound of flaked oats as part of the grain bill but I still think its not going to taste right. I used S04 yeast, 23 grams dry on a 1.095 wort cooled to 61 degrees. I’m kinda dreading it but hoping for the best. I’ll know soon. :-\
I just checked the gravity on the second batch… hmmph… 1.028. ??? I was expecting it to be lower… much lower considering how low the mash temp dropped.
Probably S-04 & 61F… S-04 likes it a little warmer IMO…