The picker has some nuance… I set mine to rec2020 and I know that my display profile is not bounded and causing an issue. So this shows me if gamut is ever out of bounds during processing. Because DT has this display profile in the way and not branched out it can for certain profiles cause a problem … In any case I think the only way to be sure that you would always get srgb values would be to set working, histogram and in some case the display profile to srgb otherwise during colorspace converstions there might be small discrepancies. Setting the output profile to srgb maps your data to srgb so I don’t bother setting my picker to that but I can set that with the softproof profile and toggle that on to toggle srgb for the picker values in srgb if I want to see them…
In my case the values don’t change for a couple of selected images claiming to be pure red…only changing the histogram profile alters the values and that is expected…