Thanks everyone for your ideas. I also have the Oxygenics but in my case it doesn't seem to play for or against the cold water shot. I've often wondered if there was a way to stop the dripping water during shutoff and thus stop the water movement to hot or cold.
OldBiscuit-I like your first suggestion on the mixing valve, might give it a try.
I also can put up with the oddities of the shower. My technique is to put the washcloth up to the shower head and rinse it while waiting for warmer water. But I do worry about the scalding water, especially when I recall the faucet breaking while I was taking a shower. But mainly I worry about guests and grandchildren and DW.