Ok sorry I probably misunderstood you. You said that 3.5 stop difference between Canon 7D and Panasonic S1 isn't that big. I assumed you'd try and show a 3.5 stop recovery in 7D.Where did I say that I recovered 3.5 stops?
But again you shadow recovery sample above shows 2.5 stop recovery, and it's hard to check on the quality of the resulting image because it's too small. So it doesn't prove anything. You recovered 2.5 stops from shadows with dark but clearly visible details, and from this post https://www.canonrumors.com/forum/index.php?threads/canon-executives-say-a-lot-more-coming-in-2019.36985/page-4#post-771313 we see a recovery from almost totally black shadows with no visible detail.
So I don't see, to be honest, how your example shows anything. The fact that you recovered 2.5 stops of shadowson an image from 7D doesn't tell us if the difference between 7D and S1 is insignificant. It doesn't even tell us if it's significant. It only shows you can recover 2.5 stops and it looks ok when downsized.
Ok, but again you example that uses 7D doesn't tell us anything about 5DIV vs S1 comparison.I posted that image to make a point to the DRones on this board who miss no opportunity to say that the 5D4 and R sensors are old tech that are so far behind Sony on DR that we're going to switch brands any day now. I replied to a posting of a Panasonic S1 shadow recovery example by someone who kept talking about how great it was to have a "new competitive sensor" implying that the 5D4 sensor is old and uncompetitive.
I use DPRSplit, it helps a bit but happens to be unreliable - the merged files sometimes have a very strong green and unfixable cast in the brightest highlights - so sometimes it helps to recover highlights, but I can't rely on it and I'm afraid of overexposing by 1 stop deliberately. I've used it or tried to use it in probably 1/10 of my recent keeper images, btw that probably shows what I'd get if my camera had 1 stop more of DR. 10% easier processing and more keepers. That's actually a lot.And if you really want to quibble about it, shoot DP RAWs and process them to add roughly 1ev on the highlight side putting those cameras on par with anything else out there, literally and to the numerical point score.