In your case I would suggest that your settings would be…
Calibrated camera icc profile for your camera if you have one as the input profile. If not let DT use the matrix defined for your camera, It should be equivalent to the standard Adobe one by default.
Working profile set to rec2020 to allow processing in a wide gamut
Display profile to your calibrated display icc profile
Histogram profile best set to the working profile so rec2020.
Some set it to sRGB and often the working profile to sRGB but really this is not necessary and actually would restrict proper color management.
Color management handles the mapping of the larger working space to the output space using the output profile, so from the large gamut to the smaller one.
Also you want to know if you go out of gamut while editing ie in the larger working space of rec2020. SInce the histogram profile provides the data for the gamut indicators this would show you true out of gamut if it happens while editing. Setting it to a lower gamut color space would not.
There was a but that sent the data to the display profile before the histogram profile so that in this case the data would never appear clipped but I think , I think, this has been corrected.
Returning to your output profile ( ie the one that will map gamut for the exported image) you should set it usually to sRGB or AdobeRGB depending on the output destination. Usually the former for display on the internet and the later for printing. In your case your monitor can handle Adobe so that might look okay exporting to that for you but for others not so much .
I have not found it in the manual but it was presented by Shane Milton that DT only embeds the export profile if you specify this in export setting dialogue. If you leave it at the default “image settings” it would export say an AdobeRGB image if that was what your output profile was set to but not embed the profile so some apps could assign sRGB to this file and this could mess up your colors…
I will have to check that to see if this is true but if so maybe something like this could be happening??
EDIT… I use xnview and it shows a correct icc profile no matter which way I save it so I think either that information is old or not correct…