Some time ago when I was playing Everspace 2, I noticed it had some great looking spaceship customization options that I thought MIGHT work well in this game too, even if in slightly less detail.
The first one is neon lights all around the spacecraft to be able to make even more eye-catching glow in the dark effects in any color, picture below is an example of the one from Everspace 2:
The other customization option is engine particles (compatible with only some engine effect types), which include various things such as bubbles, lightning, heat, sparkles, fire sparks, some darkness effect that everspace 2 did, plain dots, geometry shapes depending on the engine shape which from above will just look like horizontal lines, etc. The pictures below are some of the examples mentioned:
These effects may seem like they only look good in great detail, but I imagine it’d be somewhat cool anyway if the effects are much less detailed just so they can fit ciu’s graphics.
They could also be locked behind the chicken hunter’s license depending on how awesome the end result is fr