No, your posts are off-topic.
Downgrading without a dongle has nothing to do with vflash or petitboot, and neither does qa mode.
I'm guessing you want to downgrade because you have a 3.56+ console, well you can't, so don't ask if that's your intention. If you don't want to downgrade 3.56+, then there's no guide, it's mostly theoretical, I'm not sure if anyone has successfully used grafs tools to do it, but with the right steps it should be possible.
Now, expecting help with qa mode, something that isn't yet public, really shows how little you've researched this.
Actually research, and don't just say you did.
The otheros++ page at gitbrew lists several theoretical uses. There are no tools for qa mode, and there is no tutorial for dongle-less downgrading, just some unfinished tools that are not user-friendly.
Maybe when you come back you'll realise how uninformed your posts look.
STOP! Before you ask questions... READ the first post! RTFFP = Read The F*cking First Post
Yes, A 3.55 "jb" (cfw) is available, no >3.55 "jb" or cfw yet.
Yes, A 3.55 downgrade is available. But not to lower than stock firmware! (What it came with)
No >3.55 downgrade is out there yet.