Make fn the default function key behavior only for some of the function keys [duplicate]

I want to override F1 and F2 behavior, since I have external display and Mac can't control display's brightness. The rest of the keys should retain their non Fx

I know about "Use all F1-F12 keys as standard function keys.", but I don't want to change all of the keys to be F when pressed, just some of them. (For me single press music and volume control is necessary.)

Is there a way to pick some of the function keys to default to numbered function instead of the "Apple" definitions system wide?

Solution 1:

You can use FunctionFlip to change individual "special" keys back to their function key value.

Solution 2:

Another great way to fully customise Function keys (or any keys) is KeyRemap4Macbook

You can customise individual or key type behaviour either per application or system wide.

It's also free.

Solution 3:

A slightly clunky workaround would be to turn them all into standard function keys, and then program the ones that you want manually through the Keyboard Shortcuts section. That would obviously be no good if you wanted to use the function keys for other behaviour.