-w ETA?

[arandomusernam]

I am trying to restore an iPhone 7 Plus from iOS 15.1 down to iOS 14.4.2, using my saved blobs. As I cannot jailbreak on iOS 15.1, I have decided to use the -w argument (APnonce collision method). I was just wondering how long this should take. I was just thinking that if it has to go through every single apnonce until it reaches the correct generator in the .shsh2 blob, it could take anywhere from 1 day to a year, because of all the different possible combinations. If someone with prior experience could tell me how long it took them, I would greatly appreciate it!