Last time I was like you try searching around the keycaps with side print for backlight, at the end I give out because if you want the side print keycap to light up ( if you found it  ) your LED must be at the bottom to shine, but my Ducky Shine 2 is at top, I feel if I found also not beauty to light up like that.

Now I using PBT white keycaps to shine through effect like glowing whole keycaps, like to use it with LED function point and light up. 

Other than that using black PBT don't let the LED shine through but just let them glow at side.