iOS hacker tihmstar has posted a new teaser video on YouTube suggesting that the iOS 9.3.5 downgrade is now possible, using a third-party tool called 'Prometheus'. The teaser clearly reveals an iPhone 5s being successfully downgraded from iOS 9.3.5 to iOS 9.3.2.
If there is any truth to this claim, it will be the first major breakthrough for downgrading 64-bit iOS devices on Apple's latest mobile operating-system software. This method requires Apple's APTicket and SHSH blob system, which are the only caveats for a successful downgrade from iOS 9.3.5.
On the downside, the downgrade process is applicable only for 64-bit devices and not 32-bit models. It is still unclear if any other conditions are required to be met for a successful downgrade without using jailbreak.
Saved APTickets and SHSH blobs are the only pre-requisites to access older and jailbreakable iOS firmware via the downgrade process.
If you are still not convinced, check out the Prometheus tool for downgrading iOS 9.3.5 in action, in the demo video posted below: