Even though it is a recoiless weapon, blast is a problem with the SMAW. Due to blast effects during repeated firing (high dB noise, back blast pressures, etc.), instructors for the Assaultman (MOS 0351) course undergo alot of physiological stress during live fire and are limited to the number of days of live fire they can instruct per week and the number of rounds they may be exposed to on each firing day. IIRC the max number per instructor was six per firing day with one or two days of rest in between firing days.
Thats one of the positive side benefits in seeking to develop a fire from enclosure (FFE) version of the SMAW. If your design is going to permit FFE fire, you must very significantly reduce or eliminate back blast altogether. Do that and it will allow you to shoot from inside bunkers and from inside rooms. In addition, FFE will cut down on the physical stress to the gunners and crew (including instructors) from repeated firings of the weapon.
I'm glad to hear that "they" are addressing the problem ... one of my uncles is "disabled" (he can't hear in his left ear) due to having served as a Marine cannoncocker in Viet Nam.