I left it for a while after candy painting to add lighting (because my existing 3mm bullet-shaped LEDs just wouldn't work), but I finally got my hands on some pre-wired chip LEDs, so I was finally able to add the lights! ✌️
You can't tell from the photos, but everything except the twin eyes and main camera blinks!!
I had a lot of trouble, like having to disassemble it once, running the LEDs, and then forgetting to add a resistor while checking the lights, but it's finally finished.

Before lighting
Before lighting

MGSD Freedom Gundam High-MAT Full Burst with LED Lights | junchan's Gunpla works