Does Pwned DFU mode allow an iPhone 4 to install any version of iOS? Does Pwned DFU mode allow an iPhone 4 to install any version of iOS?

I have read 


http://blog.nialbarker.com/824/dfu-pwned-dfu-soft-dfu-iphones-demystified
http://www.blogonerd.me/2011/02/how-to-enter-pwned-dfu-mode-and-use.html


and watched


Sn0wbreeze 6.1 / 5.1.1 Jailbreak &amp; Hacktivate iPhone 4, 3GS, iPod Touch 4, 3 &amp; iPad 


Then I come up with a question: Since Pwned DFU mode allows the iPhone to download an customized ipsw created from sn0wbreeze, does it mean that Pwned DFU mode allow an iPhone 4 to install(upgrade or downgrade) any version of offical iOS without requiring an SHSH blob for the corresponding iOS?

A screenshot to show the ipsw difference, using iPhone 4 ipsw with sn0wbreeze Simple Mode.
You need those SHSH blobs. I've tried almost anything else available online, without success. Updating to the latest version via restore (without the blobs) is no problem ofcourse.

When you jailbreak your device it will store the SHSH blob on Cydia server, as you can fetch them from their servers with your current device UID if lost.

A SHSH blob is a small piece of data with Apple's signature connected to your device ID.
Since you can only validate iOS versions with your own device ID, there's currently no way to install previous versions without having "your" blob.

Good luck!