I have a theory when it comes to flo-orange. I've spoken with people in the industry about it, but they are some what evasive about their manufacturing process.
I could never figure out why some guys got picked off by wearing flo-orange and other guys didn't. I took it upon myself to buy as many diiferent garments as posssible and started doing my own field test.
My conclusion is this; There are two distinct different types of flo-orange on the market. One made with yellow dye, and one made with red. The flo-orange made with yellow dye is almost neon in appearence, especially to deer. The flo-orange made with red dye is a non-issue because deer can't see red. The differences are subtle, but can be seen by the human eye when the garments are next to each other.
I personally have found that uv-killer is more of a gimmick than an actual aid. However, if it works for you I'd stick with it.