Back again with another suggestion! I must be getting a bit annoying at this point. Sorry about that. I vertex colored some geometry partially white to simulate the bottom being lit using the vertex colors as an emission map value (so that the light and texture don't have to share a UV space) and immediately came to the conclusion that it could be significantly improved by adding an exponent property to the shader to control the falloff. Here's an example showing an HDR emissive color with a brightness of 3 filtered through a half black and half white vertex colored cube, which has no bloom at all and a reduced falloff due to the brightness; and, below that, the same color with a brightness of 10, which has a nice bit of bloom, but with an even less noticeable falloff. The objects are not sunk into the liquid; they are sitting on top, scaled down vertically. Ideally, I'd like to specify an exponent value to add some intense falloff so that the very bottom blooms heavily while most of the object remains primarily colored by the texture. This would visually ground the object in the liquid and give the impression that it is being aggressively corroded. So, my suggestion is simply to add an exponent material property to the emissive map.