Nice to see back at work on this. :celebration:
Ok, maybe it's the right time to set up a little wishlish. :dance:
Don't want to urge you in any way. Just see it as an additional source of inspiration. So here's what I'd really like to see in the future:
* underwater caustics (maybe depending an current weather condition and/or daytime)
* underwater godrays (same as above)
* (subtle) underwater fullscreen wobbling/refraction effect (the old one never worked for me, sorry)
* floating plankton particles (maybe in different layers)
Don't even know if it's all possible, but on the other hand: looking at the recent developments on MGE shaders I think no one will ever even dare to speak the word 'impossible' within these forums.