Announce Fn key toggle state for the benefit of machines that pass this information to the OS

[adlevision]

Is your feature request related to a problem? Please describe.

Because the Fn key lock state is not announced by NVDA, identifying the key and determining its state can require trial and error. As several users describe on this thread and this one, those of us with Microsoft Surface devices frequently discover Fn Lock has been toggled without our knowledge; because, unlike on keyboards that use a sensible combination like Fn+Esc, Surface laptops use a press of the Fn key by itself. This is not an insignificant frustration.

Describe the solution you'd like

As of Windows 10 Version 1909, "Narrator and other assistive technologies can now detect the location of the dedicated FN key, and determine if it is locked or unlocked." JAWS likewise announces the Fn Lock toggle state on surface devices. While not all manufacturers have made the switch from hardware key to OS-detectable toggle state, some others likely have or will do so in the future.
In short, NVDA's announcing the state of Fn lock would be consistent with its announcement of Caps Lock and NumLock on machines that implement this capability.

Describe alternatives you've considered

AutoHotKey can probably do it, but only for advanced users willing to take a hit on battery life.

Additional context

[LeonarddeR]

I tried this on my Lenovo Yoga Slim Pro from 2021 and there, Narrator is unable to report the FN toggle key state.

[adlevision]

Users of Dell and Hp machines likewise report Narrator doesn't do it, though I'm not sure of the vintage. I suppose that doesn't make it 100% certain that only MS exposes it, depending on how it works under the hood. JAWS theoretically might grab onto something; no reports on that. I did learn that Lenovo, Hp, Dell, and I think Acer store their UEFI settings in the registry and can toggle Fn Lock through PowerShell. That doesn't sound useful in real time, though.
The frustration is significant enough for me on the Surface that I wish I hadn't bought it. I've been using a Mac, plus my desktop keyboard likewise puts the left control key right where the Surface Fn key is.
The issue surfaces for me (no pun intended) most often when I reflexively hit the "shut up" key, because I've been able to remap the Copilot key to right-control using SharpKeys. That only works when Fn-Lock is on, when the computer sends the Applications keycode instead; and, because NVDA doesn't announce when the Copilot window comes up, every couple of hours or minutes I find out the hard way I've toggled it.

[SaschaCowley]

Narrator announces the fn lock state on my ThinkPad P16s Gen 2, so this is something I should be able to work on.

@adlevision said

I did learn that Lenovo, Hp, Dell, and I think Acer store their UEFI settings in the registry and can toggle Fn Lock through PowerShell. That doesn't sound useful in real time, though.

Do you have a source for this? We may be able to do something with it.

[adlevision]

One of the Google hits is linked below. AFAIK, this wouldn't apply to Microsoft or other brands not listed. What I was hoping Windows 1019 added was to provide support for bringing Fn Lock in line with other toggles (Caps/Scroll/Numpad), how ever those are done, which would seem not to require much from NVDA and would almost constitute a matter of protocol. I don't know anything about the change other than what was in the Microsoft note linked in the ticket, though, which someone pointed out on the .io group.
Using PowerShell to Configure UEFI