I was under the impression he played a shit ton of DT in Green Bay. But obviously my memory is shit.
Nothing wrong with your memory Ram Bro, at least not in this case. Reggie started at LDE in his career, but in the course of a game they moved him into the DT spot on occasion to create an unbalance.
Another thing about Donald to add. We have never seen 1 OL beat him regularly in a game. But back in the day even the great Reggie had his hands full 1 on 1 with Slater and Jacoby. Youngblood would have great battles vs Yary, Dierdorf, and Rayfield Wright (Cowboys). Deacon and the Packer's Forrest Gregg would butt heads one on one too with very little if any double team help. Every one had their single nemesis on the other side where they would win-lose throughout a game.
But Donald... have we ever seen plays of one lineman neutralizing him more than once? I'm sure there are some that got in his way, but finding one guy vs Aaron, especially in these days of free agency and player movement, is like trying to find a needle in a haystack. But then Donald is moved around a lot more than these other defenders too.
Youngblood filp-flopped with Dryer in his 2nd year under Prothro and sometimes lined up on the right with Dryer on left. But from 1973 on he was strictly a LDE.