Let's continue reading on the page in Palmer to answer the above question: "This aging is more important for the highly toasted malts, toasted for more than a half hour (dry) or 1 hour (wet)."
This has been my personal experience. I often dry toast base malt and oats for my special bitter and use them the same day. No problems with flavor.
__________________ Reformation Brewery: We went professional
Obsessing over: starting a local brewery (hence I am not here much these days!), Pickles, my wife, 3 year old and 6 year old
Reading: fall of giants by ken follett
Building: gardens, recipes, and trailer mounted smoker/ wood pizza oven