I’ve used iBEC, iBSS, ASR and KernelCache / DeviceTree patches to make sure the CFW is not fired out by ASR module inside Restore Ramdisk.
The iPSW I created Is a combination between iOS 9.0 for which we have ROOT and IV keys and iOS 9.1 (to get blobs) for which the keys aren’t available yet.
Notice: This video is highly outdated, therefore, the links were removed. Please check out a more up to date video on the channel.
I recommend following this updated video: https://www.youtube.com/watch?v=maBWXMhY92g