So, it turns out that you CAN map all controls to one controller, using 2 button combos.
It took me ages to work all this out, so I thought I'd put this up, as it might be helpful to someone.
Obviously, there's personal preferences, and no 2 peoples set ups would be the same, but there might be some ideas here that help.
I use the left side + button, and the two front buttons as modifiers, then XYAB and the trigger & front buttons.
The left + button also controls thrust left, right, up & down, but this doesn't affect it's use as modifiers, except for a little harmless boost in one direction or other.
I've avoided too many one-shot buttons, as they keep getting triggered by accident.
It took me a while to get used to the controls, but once it starts becoming 2nd nature, it all gets much easier.
In this diagram, the modifier button is red.

- - - Updated - - -
One missing bit of writing is the B button on Weapons & gear deployment, which should read 'Shield Cell'
It took me ages to work all this out, so I thought I'd put this up, as it might be helpful to someone.
Obviously, there's personal preferences, and no 2 peoples set ups would be the same, but there might be some ideas here that help.
I use the left side + button, and the two front buttons as modifiers, then XYAB and the trigger & front buttons.
The left + button also controls thrust left, right, up & down, but this doesn't affect it's use as modifiers, except for a little harmless boost in one direction or other.
I've avoided too many one-shot buttons, as they keep getting triggered by accident.
It took me a while to get used to the controls, but once it starts becoming 2nd nature, it all gets much easier.
In this diagram, the modifier button is red.

- - - Updated - - -
One missing bit of writing is the B button on Weapons & gear deployment, which should read 'Shield Cell'