What exactly are hotstrings for?

[Harem]

Step 7
Now switch back to WoW, specifically, the Mage window, make sure both the Mage and the Priest have an enemy target selected, then hit the 1 key on the Mage, the 0 key will be pressed on the Priest and they will both fire off their spells.


Note: This behaviour will not be reversed, hitting 0 on the Priest will not hit 1 on the Mage, to do that, you will need to add in another hotstring.

Still missing something here.

Loading A.kcl on the Mage instance creates the hotstring 'test' whenever 1 is pressed - right? This hotstring is translated via the B.kcl loaded on the Priest instance into the key O. So I guess I'm not understanding why pressing O on the Priest isn't doing the same thing - sending the 'test' hotstring to the Mage instance which gets translated via the A.kcl into a 1 keypress.

If we are mapping a key to a hotstring and then we tell different instances what they should use for a keypress when they recieve that hotstring - then how doesn't it go both ways?

EDIT: Maybe you meant hitting 1 on the Priest will not hit 0 on the Mage?