I think I can make a lot of smoke at high temperatures by adding smoke wood to the ash box, but I haven't gotten around to it.
I took a sous vide tri-tip out of the refrigerator and finished it at 400°F in the Masterbuilt 1050 last night. The wood in the ash box burned and made clean, thin, blue smoke. It had nice smoke flavor and a pronounced smoke ring. So I'm thinking that there are more high-temperature smokes in its future.