The main thing that I would want out of a modded concealed display would be for Ka to stand out better.
Then I had a thought, what if I just cover the X and K LEDs with black tape.
Bingo, works perfect.
Now it can be dark, with music blasting and I can quickly visibly confirm if it's Ka.
If no band light is showing when the arrows light up I know it's K (X Band is off).
If a Band LED lights up then I know it's Ka or Laser.
I may go for color display but this does most of what I want for about 4 cents.
And is completely reversable.
You could take it a step further and mask the laser into the shape of say a triangle.