Thought I'd chime in here regarding HDR considering I have an OLED TV. My SDR and HDR settings are about as calibrated as they can get without going that extra mile and hiring a calibrator, which much couldn't be done for the game modes anyway due to their limited settings. I have a 2016 C6 OLED on an older firmware that had a brighter HDR tonemapping at the sacrifice of some highlight detail. I enjoy this balance and have kept my TV as such.
Most HDR games I play are fine, but being an OLED TV means that some HDR games with raised black levels stick out badly. From personal experience, RE7 was particularly rough. That game was washed out badly on my OLED, the solution being turning my TVs brightness down, or playing in SDR. RE7 stuck out due to all those wasted perfect blacks, and I'm more or less seeing the same thing here in Red Dead Redemption 2.
There is no texture quality difference, or actual visual drawbacks to HDR on RDR2, but merely the game is rather washed out to the point where shades of black are instead shades of grey. This seems to be a recurring problem with bad HDR implementations on the OLEDs in particular. I don't really know why this continues to happen, but I do remember reading someone hypothesise that a lot of developers are tonemapping the HDR on PC monitors with really aggressive local dimming, the result being raised blacks for people with high end TVs.
The solution to the HDR problem in RDR2 is really easy. Just go to your TVs brightness setting and notch it down a few until the shades of black are actually black, all that colour and contrast will return, along with some slightly better highlight detail. I've just been playing in SDR because I play a lot of HDR games and it's just too frustrating to be making this adjustment every time going into Red Dead.
Also, I'm playing on the Pro. I do have an X but stuck with the Pro for this release, my friend bought it on both. Although the Pro version does look soft, and the X does look considerably sharper, the Pro version still holds up fine. He has the exact same OLED as myself, and the X version also suffers from a washed out HDR implementation. One thing I appreciate with my PS4 version of the game is the ability to turn off HDR in-game, that is oddly missing from the X version. I've got another friend with a 2018 OLED that I was curious to see how the game looked on, but he's got some pretty butchered vivid mode settings going, so it wouldn't be the best comparison.
My biggest problem is my damn launch Pro and its fan. It's the inconsistency more than the noise that gets me, I'm actually using a small room fan to drown out the Pro fan. Besides that, I'd suggest to people having problems with HDR to adjust their TV brightness slider, and if they are unhappy with the softer look of the Pro, maybe, only slightly, adjust your TVs sharpness setting. Although across the board I'd suggest leaving that setting on 0.
Also, the X version itself even though it's native 4K doesn't look as sharp as Forza Horizon 4 or anything like that. The game still has a soft look due to the AA and other more technical thingy things. So I wouldn't be expecting Rockstar to make any big changes to the Pro version with patches. If anyone is holding out, you might be holding out for awhile.