Performance: Expect Zero impact on FPS/performance.
HDR Screenshots: I am more than happy to oblige to this request however at present~ I am very sorry but I do not know how to take 1:1 HDR screenshots. :( When I try to take screenshots the capture always comes out washed out, too dark, too bright, and/or overly saturated.
HDR screenshots are hard to do as the relevant image file type for HDR is not widely supported and most computers can't capture it correctly. I guess you could take a pic of the screen with a phone, but that presents its own issues.