Super happy you found your style and it works for you.
I'm not sure how I am destroying data by adding RO automatically? To me, if anything, it is giving me better resolution on the data available? Like smoke running 700 scale vs 500? Same data as yours, but mine is watered down?
I could grow the same way as you by turning off the valve on the float valve, and my water would drop with use. Then to maintain I would top off with RO and add nutes right? The only difference is that in mine the top off is continual, further dropping EC more quickly via dilution. RO water will not effect the PH info either way with auto top off or not. So we are just talking about EC. If you are chasing PH swings, it is not because my RO adds buffer to my grows or something.
I'm also measuring how much they drink daily on the water line in the RO res.
Am I looking at this wrong?
Thanks bro, appreciate that. Gonna try to expand a bit here, see if I can show you exactly what I mean here. And please keep in mind, I am still trying to understand all this and why it works the way I have seen. I don't have those answers, just been trying this out to see if there is anything to it, and I believe there is.
What I am seeing is there is a complex relationship between the plant, and the water EC and pH. Pretty sure you are familiar with the chart I am using-
The first thing I had to figure out is how to read the chart. Of note, look at EC first, then pH. Also, right side on the chart is for a res with a rising EC, left side is for a dropping EC, so I look at the EC FIRST multiple times each day and record that, usually mornings and evenings but more often if I am trying to get an unstable res stabilized. What is it doing? I had thought it's best to look over a course of at least 3 days to determine a trend, but have realized you can see this same trend almost immediately after making any changes to the water, like later in the day you can measure and see the trend. Then follow the chart on what to do depending on first, what the EC is trending, and secondly, where the pH is trending. Middle-middle/right on the chart is where ya want to be.
This, I believe, is where the plant comes into the equation. It's getting the water + nutrients and immediately does what it's gonna do and start eating/drinking. Based on what it needs, something is happening in there to make the pH move or stay stable. If the nutrient needs are right in line with what the plant wants, the pH changes very little, and I have found that window several times now and it's not a big window either. The opposite is true when there is too much or too little nutrients in the mix. I have found ppm changes as little as 30 will either make or break pH stability.
If you run a top off res, none of this information is available to you because no matter what is going on in your root zone, if the plants are drinking, your EC will fall from dilution alone but could also be falling from having too little nutrients in your res. You do not know which one is the real culprit with an auto top off. In my mind, it's a guessing game at that point. What? You threw out your GH feeding chart? Good on you, threw mine out too. Starting point for my res? I know a lot of guys like to start at 200=300 for new seedlings or clones. Is that a good place to start? Perhaps. That is what I am doing but quickly realize that 300 number is way too hot. How did I learn that? Not from the plants themselves. I learned it from the water and what that is telling me. Haven't nute burned one yet.
You have not destroyed any data in a sense, but rather, have made a situation where that data is impossible to collect. That is kinda why I called it a gauge like something on your truck dashboard. Gauges tell us things. Sometimes we have cars with no gauges. Do we need to know our oil pressure all the time? Probably not, but it's nice to have that there instead of a dummy light.
My RO water does affect my pH in that it will usually bring the pH up. My RO water is about 6.8-7 pH and will always bring the pH up a bit, more or less depending on which system we're talking about. 2 gallons of RO will raise the pH way more in the smaller systems than in that 4 site where there is almost 30 gallons in there.
So when I do my top offs I also use this info because I want to mimic my res in my top off as closely as possible, so that is what I do, in the proper ratios of course. I don't have to guess how much to add for ppms, I just make it the same as what is working already. The only guessing is geting to know the nutrients and how much to add of each to get to your target ppm, which I have found is fairly easy to do. Top offs do not need to be perfect, just close.
. Not sure I have time for all this monitoring and adjusting. 
