Your Samsung TV is not capable of displaying it in DV no Samsung TV's can do this as they do not have the chip installed required by Dolby to do this. It was just an example I gave. But if I choose to watch Valerian in HDR10 by changing the setting on the Oppo 203 to HDR Forced, I can watch it in HDR10 and the picture still looks spectacular to me.
Not all 4K blu rays which have the DV layer will show this on the sleeve of the blu ray. But you can always find out if a certain film has the DV encode by checking out reviews of the disc from certain sites. For you it's irrelevant anyway as your set is not able to show Dolby Vision. And 4K HDR blu rays will have the HDR10 encoded, which your set does and the small banner pops up when the TV receives the HDR10 signal. So with that mode you have no issues at all.
Just look for the banner across the top and in the corner like this;
View attachment 357580
I also don't agree that size is not important for enjoying the best immersive experience, plus viewing distance, the lighting in your room (important for LCD TV's), and a pro calibration.
With streaming via Netflix for example in 4K HDR10 or DV, the experience can be hit and miss I find and the best way to really experience it is via your Oppo 203 with the full master audio encodes and not the 5.1 DD or subpar Atmos via streaming services.
IF you are not getting the WOW factor from your Oppo then something is wrong in your settings or with the settings on your TV. You need to read some of the owners threads for your set up on AVS Forum, AVForum (UK) for the best answers. As well as going through the owners manuals and checking you have your equipment set up correctly.