The only Global hotkeys you can configure are the ones on the
Character Set Slot options. The hotkeys you set for ISBoxer mapped keys will only work when you have a game window as the foreground Window.
So if you happen to have a browser window as the foreground, then pressing your hotkey to bring all game windows to the front wont work. You need to cycle through the Global Hotkeys you can set per slot.
If you happen to have a game window on the foreground, you might be able to use several
Window Focus Actions, and send them to each slot. YMMV.
If you want a specific slot to have focus at the end, (maybe a main slot), then you could set all the slots on Step 1, and in Step 2, have your preferred slot, then setup the mapped key to execute on "pressed OR released", then step 1 should focus them all (bringing them to the foreground) and step 2 will bring your preferred slot back to the current foreground window. You could try the
Window State Action too.
This all assumes that you cant be using the Window Layout feature, "Always On Top, if a game window is active".
edit: must be tired. Val pretty much said all that anyway...