Hey, I'm glad to see you taking the time to play around with positioning and hearing the results of your efforts
It took me about a week of messing around with it off and on before I settled on where they sit now. They sound pretty good even when you don't have them dialed in so it's quite a shock to hear them once you do. They do image like crazy!
Here are a couple of pics of what I ended up doing for driver supports. Blocks of foam
meticulously carved to conform to the driver radius with an electric knife
I will probably do something a little more aesthetically pleasing in wood at some point but I'm perfectly happy with this solution for now.
RC