You can put convential platforms on stud wlls, you Have to put triscuits <actually named Stressed Skins> on stud walls.Interesting. I believe I've seen conventional platforms on top of studwalls, no legging to mess with. Yes, I'm near certain it was conventional platforming.
Actually you could place triscuits on blocks but they work best on stud walls. The walls, however do not need to be 2x4 then can be 1x4 but you need to be sure to add torsional suport, a cross support or have one side covered with 1/4 " luan like a flat.