I don't have the experience to answer your questions but I will say that I've just about convinced myself that I'm going to make a grilling insert that goes right above the firebox throat within the cook chamber.
Here's where I got the idea. They claim to get temps up to 700F of a normal sized smoking fire. Call it a grill, flat iron, griddle, wood oven, whatever... I'm excited about this idea! https://outlawbbqsmokers.com/hot-box-insert
I'll probably combine that idea with a baking steel: https://www.seriouseats.com/2014/04/the ... teelg.html (I drool over the steak pics on that post)