Do you mean something like "Ctrl+Trigger", "Alt+Trigger" and such? Not in that way, but another way, yes.
First you'll have to map the four Modes into your keyboard. You know, Clipboard->Options->Controls->Map keys->Global->Mode[1/2/3/4] select. Save the mode settings.
Next go to "Map controllers", select another Mode than Mode 1 and map all the buttons you wish.
Let's assume you've just mapped the modes logically to keys Alt+1, Alt+2, Alt+3 and Alt+4. In the normal flight mode (Alt+1) your trigger will most likely make your primary weapon shoot. Mode 2 could have the same trigger to be assigned to open Clipboard, Mode 3 bail out and Mode 4 check 6. You can change them in flight, the radio buffer will inform you by a "Mode # selected" message.
I'd not recommend using variations on vital combat controls, though. The example above would be suicidal if you had left Mode 3 on while sneaking to the enemy's six...
Happy tinkering!
