No, you have about summed it up. Numerous studies have been done on many fish species and of the ones that I know of that have been tested, trout and salmon can see some UV, but other then that, only the "Minnows", to include carp, can see UV.
The fact is that UV does penetrate water the deepest, but it is not a color that can be seen by most fish.
The fact is that UV does excite fluorescent so that they are more visible.
The fact is that you cannot add a UV reflector to your paint and actually make it visible to fish, except as noted.
For the nay Sayers, they take very small pieces of the fish retinas and expose it to light of different wave lengths. They then check for chemical changes in the samples. If there was a chemical change, then the evidence is clear that the rods and cones were receptive to the wave lengths. So far, they know that the sunfishes see Red through Blue. They know that walleye see mostly red and green, so when you catch them on blue or ...... they are probably seeing it as black. Black is not a color, but a lack of color, while white is not a color, but a combination of all colors. They know that trout and salmon can see near UV through red. They know that the minnow family can see UV through infrared, a very impressive ability.
The fact is that NOT ALL fish have been tested, so......... Who knows, if your target it Tarpon, then I don't have a clue. If your target is Marlin, again, I don't have a clue.
One more fact, a side note that can mess the entire argument up. I will use Walleye as an example. The peak reactions are at Red and Green, but we all know that Orange and Yellow are between those two colors. Yellow (a primary color) does cause some reaction on the green receptors and orange (a secondary color) does react some on the red side, so in reality walleye do see from green through red, but we must assume that they see a blend of green and yellow or red and yellow like we do. Who knows anything for sure??????