[ChuckG]

The problem I had that made me start making baffles as your first illustration was because I use simple manual float valve that will open and close with agitation. Although it wouldn't be enough to change the salinity in the tank or anything like that, it was enough to turn the RO/DI unit on and off repeatedly. Had I not had a pressure gauge on the RO/DI unit I don't know that I would have even noticed that but it was enough to send my pressure gauge crazy to the point of vibrating back and forth and making loud noises. I "assumed" this couldn't be too good on the auto shut off either.

Rather than connecting directly to the RO/DI unit I changed and use a secondary storage tank. It's all still connected but I now have to switch the water on and off to fill the resorvoirs every couple of days.