The RO/DI doesn't need to be stirred, aerated, or heated. Whatever you end up doing with the water will make it a moot point. You will either put it into a salt mixing barrel where you will heat and mix (aerate) it, or you will put it in a tub for top off where it will just sit and get cold anyway.
Honestly, I would be ticked right off if I had 8 ppm going into the RO and having anything other than 1:1 water ratio. Most membranes suggest 4:1 which is for flushing the membrane as it runs to keep it from scaling, but with only 8 ppm going in, imo you don't have much to worry about. That RO membrane will last you probably 5+ years with that little load you're putting on it.
With 160-180 ppm my RO membranes last 2-3 years. I would rather replace my RO membrane once a year than waste that much water. So far, I haven't had an issue though...my membrane is lasting just fine at 1.5:1.