g selects the position in the grid by the top left point(origin) of the window. Drag window roughly where you want it and hit 'g'.
Click on another grid, then you can see the one that had the check. Otherwise then I have to make some Gui where the tray icon is good enough. If you look at the grids all the 3 section grids are the same as the first only rotated. So if 'B" is selected and you can't see it, look at 'A' and rotate it clockwise 90 degrees mentally. Likewise if you have 'F' selected, it's the same as 'E' only rotated clockwise 90 degrees.
The question about 'l' I don't understand. If you have an editor and you type 'l' the letter is going to go into the editor. That's why the hotkeys.
If you mean why do I have it so you hit a hotkey, then it waits for a letter, then it's to reduce the number of hotkeys. The more you have the greater the chance it's already in use.