[OJFord]

From the submission:

> Once System Firmware is updated to the macOS Sonoma version, if the display is configured to a refresh rate other than ProMotion, that system will no longer be able to boot into older macOS installs nor Asahi Linux correctly. This includes recovery mode when those systems are set as the default boot OS, and also System Recovery at least until the next subsequent OS upgrade.

That can and will absolutely affect regular users, even if they don't 'care' about it or 'know what it means'.

[eddieroger]

> that system will no longer be able to boot into older macOS installs

No, that seems pretty super-user to me. The average user goes forward in versions, not back, and rarely has two at the same time.

[cstrahan]

> No, that seems pretty super-user to me.

Here's a play-by-play scenario.

1) Grandma is prompted to update to Sonoma, and so she does.

2) But note that the installer does not update the recovery partition.

3) Laptop reboots, and grandma sees an Apple logo for exactly 2 seconds, and then the screen goes black. Manually rebooting results in the same thing, every time.

4) Grandma now tries to roll up her sleeves and see if she can fix it. She googles around, and discovers that the she should be able to get into the Recovery OS and maybe fix things there... but when she tries to do that, same thing: apple logo for 2 seconds and then black screen.

How did I come up with this play-by-play? Well, because today I was said grandma.

Where does this involve the average user going back in versions of their on volition? That's the whole point of why this bug is horrible: you get no say in the matter. You upgrade to Sonoma, and depending on your refresh rate, you can't boot into your OS. Wanna use the Recovery OS? Too bad: that's too old to know to use a functioning refresh rate settings (because the installer left the old Recovery OS version in place), and instead it uses whatever was set in NVRAM (or similar) from when you last configured the refresh rate.

Wasted today using another MacBook to update the Recovery OS via DFU (using Apple Configurator), and now I'm reinstalling Sonoma from that recovery, and praying that this will unbrick my laptop for work tomorrow.

[OJFord]

On the contrary all normal users have two at the same time, that's the system recovery one mentioned.

Normal people don't care about it, talk about it, or think about it, but may come to rely on it - or have it used by a 'Genius' when something stops working. It affects them.