I suspect that you could get most of the speed and ease of installation of regular girts, along with the extra rigidity of bookshelf girts where you need it but doing all regular girts, but then lay a 2x4 on-the-flat across the top of the regular girt as a stiffener. Probably be a good option for the kitchens or bathrooms if they land on an exterior wall. Wouldn't act as a thermal bridge, get to keep the 8.5in wall thickness, and it can prevent dense-pack blown-in from settling too much. Well, in my head at least. Also, I think if you opt for blown in rockwool you don't have to do sealed fire blocks.
