My experience with keyboards has been that if they're not made by Apple or Matias, they can do nothing during startup. (No Option to choose drive, R to open recovery partition, C to startup from DVD, etc.) Most of the mechanical keyboards I've looked at are made for Windows but are Mac compatible. I doubt it. Does anyone know of extended size, mechanical keyboards that are absolutely 100% Mac compatible?
Apple don't make wired keyboards any more but Matias do. Matias make both mechanical keyboards and ones like the newer Apple keyboards i.e. with scissor switch mechanisms.
As you said Matias will be 100% Mac compatible.
<<if they're not made by Apple or Matias, they can do nothing during startup. >>
I think you will find that if they are connected to any kind of Hub or Dock, rather than directly to a USB port on the chassis, they are useless to direct startup.
In my experience, the manufacturer is a don't care.
I contacted MacAlly. Fewer than half of MacAlly's keyboard models can communicate with the Mac during startup. The expensive Macally Backlit Mechanical Keyboard you linked to is not one of them.
The Apple keyboards can be connect via USB if you don't want to use Bluetooth.
Hub versus direct USB connection is not the issue. If you have a non-compliant keyboard plugged directly into a USB slot, that keyboard still won't do anything during startup despite working perfectly after startup.
I need a mechanical keyboard fully compatible with a Mac
