I got the go-ahead to proceed with this blast shield design after consulting with the folks at BRSAero. When the rocket departs the tube, there's a significant concussive force radiating from the top of the tube before the rocket completely departs the aircraft. Since the rocket assembly is fairly close to the pilot's head in my installation, this small blast shield will hopefully provide some measure of protection.
Material is 0.025" sheet, bent in my trusty brake, and a right-angle bracket provides an attachment point to the roof (Image 2) via 3 #6 stainless screws into rivnuts.
Image 3 shows a side view through the egress window. Flush rivets are used to attach the shield to the aforementioned bracket.
single piece of 0.025" aluminum
bracket is attached to roof with steel rivnuts
flush rivets on inside of shield so nothing hangs up