I updated to iOS 15.1, here's how I did it. (Patreon)

The device I updated was jailbroke already. It is an iPhone X.

Using a package manager add these repos.

https://repo.cadoth.net/

https://repo.supervise.me/

https://dhinakg.github.io/repo

I installed Supervise, then Dallas. Dallas installed OTAEnabler and it does require you to reboot the device.

I then go to https://dhinakg.github.io/dallas and installed the Dallas Enabler profile, then scrolled down and installed Dallas 15.1 profile. Device will ask to reboot after installing Dallas 15.1 profile.

After go to settings > general > software updates and it should show 15.1. If on unc0ver you may have to turn off block auto updates in unc0ver settings.

I'm not sure what models are supported by this method, but it did work on my iPX.

Should I update my device if i'm jailbroke already? Is a jailbreak coming soon?

Sadly I don't have the answer to this. My daily device is on iOS13 and all my phones are jailbroke (except this one now). I'm updating a device because I must update my tweaks if/when a jailbreak is released. I could care less about what Apple has added if i'm completely honest.

I do think a full jailbreak will take some time and many if not all tweaks will not just work when a jailbreak is released. Can you run stock for awhile? The exploit exists, but jb devs still need to work around some issues. The jailbreak teams are active so that's good sign. 

Even checkra1n has had activity. (screenshot taken 3/6/2022 @ 11pm central)

Couple questions from my Twitter.

iOS 15.1 is not signed anymore. This method used a device that was jailbroke already.

I'm not sure how to update on stock device.

I am not aware of a method, but have seen posts talking about this and FutureRestore. I would look around https://reddit.com/r/jailbreak or check their discord.

While this doesn't explain what isn't installing or what device. I did find this while doing research.

"For those having issues with downloading Dallas 15.1 and getting the Safari error, just download TrustEvaluator  from Cydia before attempting to download. It worked for me." - Remizart

If you have some questions hmu on Twitter, if I don't know the answer i'll rt for you and hopefully someone has the info you seek.

https://twitter.com/junesiphone