The excellent teamwork between KM and BTT makes it possible to achieve something that both apps can't do on their own.
BTT doesn't have palettes and KM can't show and hide palettes by pressing and releasing a key, which I find very intuitive.
So a KM palette works like a modifier with a built in screen that displays the (single letter) shortcuts.
I tell you this because I know that many use these two apps together. Maybe someone will find this as useful as I do. 
Can you explain what you mean by this?
Hi Neil, sure, but you're unlikely to be interested since you don't use shortcuts. Right?
The normal procedure with palettes is like this.
A shortcut shows the palette (for one action or permanently). Then you press the single key trigger. Then press the same shortcut again to make the palette disappear.
That's ok, but better is, I press and hold a key, the palette appears, I press a letter (the trigger) the action is executed, I release that key again and the palette disappears. Just like you would do for ⌘ + letter.
I don't have to set if the palette is visible for an action or permanently. As long as you hold eg ⌘ pressed, the palette is visible.
This is especially useful for navigating in a text with j, k, l, etc. instead of the arrow keys. Does this make sense?
edit: Concretely in my case. I press and hold the "4" key (which I can reach blindly with my left index finger), the palette appears. now "j" becomes arrow left. If I release the "4" again, "j" is "j" again, because the palette disappears. 
Makes perfect sense. Good explanation! So as long as you're holding the palette key, you could trigger as many macros as you like, then release?
Yes! And this is really useful and intuitive for me.
You may ask, why doesn't he just use ⌘j and ⌘k etc? Because those shortcuts are already occupied.
So "4" with the palette is a new "modifier", so to speak.
And presumably "4" can be used as a typing number if you don't hold it?
Unfortunately not. If I want to type "4", I have to type fn + 4. But that's not a problem. I don't need the "4" that often, except for these explanations 
