iPhone 6+ : 9.3.5 to 10.3.3 ?

[earlrocksya]

Hello Everyone,

My dad has an iPhone 6+ with iOS 9.3.5. I recently bought him a pair of AirPods which supports 10.3.3 and does not recognize the battery functionality on his phone. I saw on ispw.me that 10.3.3 is no longer signed for the 6+. Since I am technically not downgrading the iOS can I still install this firmware via iTunes or will it crash and force me to upgrade to iOS 11?

I would hate to upgrade to iOS 11 on his phone as it already seems sluggish based off previous experience. I am hoping this method will be fine since I am going from old to new.

Ideas ? Thoughts ?

Thanks

 

[Hal~9000]

You can only install iOS versions which are currently being signed by Apple: 11.2 and 11.2.1

 

[eyoungren]

Since I am technically not downgrading the iOS can I still install this firmware via iTunes or will it crash and force me to upgrade to iOS 11?

Apple doesn't care what you call it. You can call it a multigrade crossover special for all they care. It doesn't matter if Apple isn't signing it.

And as mentioned, 10.3.3 is not being signed.

Your choice. 9.3.5 or iOS 11, latest version.