I felt asleep while reanding all the posts from the original thread yesterday, saw the videos for buoyancy but didn’t see any comments on how to make it work. Will continue reading today and I will take a look on the 4.17 you uploaded, before touching anything, so I can at leat see if I was going to the same direction. I really want to try doing myself thou, since I want to be able to support future API changes, because as you saw it is a hard task to find information about the changes. The only quick guidance is the LensDistortion plugin Epic provides and that might not be 100% with all the things you might need.