One nice thing about Apple computers is that Bluetooth works before the OS is booted. I’ve heard some motherboards with built in wifi can enter the bios using

One nice thing about Apple computers is that Bluetooth works before the OS is booted. I’ve heard some motherboards with built in wifi can enter the bios using a long power button press or something, and pair from inside the bios. Some Bluetooth adapters can stay paired after a soft reboot too. Both of above I only know about from seeing people complain online that these features don’t work. There are some usb Bluetooth adapters that let you pair directly from the adapter to a keyboard, no OS required once it’s set up. Some keyboards have an optional usb cable you can use. You can also use a keyboard with a proprietary usb wireless adapter, that is a normal usb HID device. All Logitech keyboards come with this even if they support bluetooth, probably because tech support is a nightmare otherwise. Amusingly, Logitech Bluetooth devices sold for macs are the same products but simply leave out this adapter. Come to think of it, I use normal bluetooth devices with a windows desktop and at least once a month I need to connect a usb mouse to turn Bluetooth back on (it’s easy to turn off by mistake) or because things just stop working.