I recently bought a pair of Hillbilly full fingered gloves.
However the front splints were very restricting, so I flattened them out a bit using a hot air gun. Problem is although it has improved them,they are still awkward to use.
I definitely want the back splints to prevent hyper extension and a potential broken wrist, but are front wrist splints necessary on a uni, and who uses them?
I own a pair of the Hillbilly half fingered gloves and I find them quite comfortable to use. However, I have used normal “work gloves” which provide protection and are a lot more flexible than the Hillbillys. As for your question about the splints: No, they are not necessary, but they do provide a lot more protection than just a leather glove. I think it is best to do what is most comfortable to you 
My main issue with the hillbilly gloves was that they disintegrated after about 4 months of use. The material holding the thumb portion of the glove was the first to go, didn’t last long after that.
Because of that I wouldn’t recommend them for summer rides in the southeast. I’ll probably get another pair with the limitation that they only be used in the winter.
My main question was whether palm side wrist splints are necessary on a uni.
I will keep the back splints as I said?
That’s funny because I remember a recent conversation in a thread questioning the need for the rear splint when compared to the need for the splint in the front.
http://www.unicyclist.com/forums/showthread.php?t=96898
But you’ve read that one. I find it useful… anything that takes some of the impact off your wrist can’t be a bad thing. When it comes to gripping the seat the front splint on the hillbilly gloves are more annoying than the front splint on other wrist guards I’ve owned, but I got used to it after a while.