The 145 F rest will tend to dry out the beer more than if you had only done a 154 F rest. The net result, I think, is approximately equivalent to what you would get if you had instead done a single rest at about 152 F for 45 to 60 minutes. Might be fun, or you might have some process reason for doing this, but if you're just doing it for the heck of it without good reason, you might want to consider it a wasted effort and just pick one temperature in between in the future. FWIW, I don't do step mashes much. I mash 90% of my beers at 150 F for 40 minutes. That's right. 40 minutes at 150 F is great for nearly all styles of beer, and wastes far less time than a step mash or a 60-minute mash, for those of us that care about time (some do, some don't).