This is slightly different question than the original post, but still related.
Is there any way to access the startup manager (holding the option key) with the Apple Wireless Keyboard (bluetooth)? I'm using Model A1314.
Does the newer rechargeable wireless keyboard allow accessing the startup manager?
I know I can boot into macOS and select a different drive from Startup Disk in System Preferences but I'd specifically like to be able to access the startup manager and other keyboard shortcuts while in the boot screen.