I wouldn't go more than an inch or so past the mid point - otherwise the door will get very hard to seal along the bottom edge.
And on the eighth day God created barbecue …. because he DOES love us and he wants us to be happy.
Current smokers: Egor (trailered RF) and Easybake (tabletop pellet drive)
I like one inch past both points (tdc) and just below the horizontal plane. It keeps the rain out on top and allows the bottom rack to be dead center. That is just me.
Current Smokers: Backyard RF Offset and Hybrid RF Offset trailer rig with Cowboy cooker and fish fryer, always room for more........