The malt should be stored in a paper bag for 2 weeks prior to use. This will allow time for the harsher aromatics to escape. Commercial toasted malts are often aged for 6 weeks before sale. This aging is more important for the highly toasted malts, toasted for more than a half hour (dry) or 1 hour (wet)
So this is consistent for flaked oats as well? I guess I had just never thought of them as malt.