Only con I can really see is that with the second design, it will end up angled when held upright. Doing so may or may not open up your shoulder/upper torso. If you could combine strap design and center placement from B with the horizontal placement of A, it might work better. Definitely experiment with different ways to attach the straps. Maybe cut slots in the core, smooth them out with sanding and duct tape, and then screw them in if you think they need the added support? It might help with the "shield breaking" problem you've had in the past.