Rib Roast... a little disappointing

I did a 4.3 lb rib roast Mad Max style. I inverted the plate setter, actually stuck a pan of potatoes on it, dropped in a raised rack and put the roast, which was in an aluminum foil pan, on it.

I let the egg go over 500 deg, put everything inside, shut it down and let it drop to 325. Let it go until internal was 126 deg. foiled it and let it rest.

The roast itself was perfectly cooked inside and tasted great. The disappointment was that the outside was not at all crispy or charred. It was a deep reddish brown. More the color of a smoked ham than beef. Not terrible, just not what I wanted.

The potatoes were outstanding. I left them on while the roast rested and let the temp climb up to 350+.

I did notice that the temp dropped pretty quickly from 500 to 325, but... did I do something wrong? The other thing I noticed was that there were no pan drippings. And there was a 15 min period in the middle of things where the temp dropped to 300 and I had to open it up a little to raise the temp, but it didn't seem like a huge deal.

Thanks