I've been adding ideas to a list and sharing them in the comments of the update posts to prevent flooding the site but as time passed some of those are hard to find now and even I had forgotten some, so I've posted them again (now flooding the site, sorry for that).
Adaptative star brightness
Sky reflections in the ocean
Custom structures in custom planets
Option to hide icons and orbits in the XML
Custom underwater effects
Droonaut movement improvements
Droonaut underwater improvements
Cursor while in first-person view
AGL based on the distance to the seafloor
Reorganized parts in the designer
Missing filters in posts section
I'll be posting soon the Vizzy suggestions from the previous list that didn't make it to the game.
The underwater wavy effect is extremely annoying