I’m preparing a Mac mini for sale. I have no mouse or trackpad. Using just the wireless keyboard, I managed to reboot in Recovery Mode and erase the HD in Disk Utility. However, the Install macOS utility is poorly designed – there’s only one hard drive (shown as an image), it has to be selected before you can continue, and you can’t get to it with any kind of normal Full Keyboard Access key combos, arrows, tabs, or whatever.
I once was able to use Mouse Keys in a similar situation, but I can’t figure out how to get them on in Recovery Mode. I’ve tried Command-Option-F5 (including the Fn key on my mini keyboard), tapping Option 5 times, and some other key combo I found online. I can get Voiceover to come on with Command-F5, but that doesn’t help select the drive. These accessibility keys are a nightmare.