Wanted to give a heads up on a major Scout crash:
I have a pretty good gigabit ethernet and wasn't downloading anything at the time, but with Stage3D Recording turned on, my iOS app crashed due to 150MB worth of Network Buffers, which I assume is a bunch of Stage3D data that is queued up. When I turned Stage3D off, there was no Network Buffer memory issue and no crash.
Unfortunately Stage3D recording does use up a lot of memory, because it's sending every single mesh and texture over wifi to Scout. If your game has a lot of 3D resources then this could cause it to run out of memory - in this case, it's not AIR that's crashing, but the OS is killing it because of it using too much memory.
My suggestion would be to do Stage3D recording when running your content on desktop (e.g. in a simulator), since you won't have these memory constraints. If you're deep-diving into rendering, then you should be able to solve your problems on the desktop, since the rendering is the same. Profiling on device is best for looking into performance and memory issues, since you absolutely have to run it on the target platform in order to meaningfully see what's going on.