I am designing a structure built with two wood double stud walls. The interior wall is load bearing. Would it be reasonable to assume that the gyp board could brace the studs out of plane? I am assuming I would have to spec a minimum panel size and connections.
I like to specify stud blocking for weak axis bracing of the studs. In cases where a building is three or four stories, the dead weight and construction loads on the building will load these studs, and in most cases this will be there long before drywall is added to the studs.
Also, if i understand you correctly, you have a double 2x4 stud wall, typically used for sound isolation. In this case you will only be sheathing one side of the stud.
I do think i have seen limits for bracing steel studs by sheathing, so some information may be out there.
Above is a snippet.