P: Improve Slideshow quality to match Develop Module rendering

Was wondering why some images aren't looking great when viewed with slide show. Just went through and worked on lots of images. Subtle crops, adjustments to exposure etc.

Turns out Slideshow is failing to render the most up to date version of the corrected images into slide show. Really obvious when I switiched out of Slide Show and back to develop. One image had been tighly cropped but in Slider Show was the original image - it is also missing the contrast adjustments. 

But the algorithm to generate the slide show seems to be outdated or still using something that appears to be heavily compressed or more noisy. Images that are super sharp in Develop are slighlty blurry in Slide Show. Maybe it's still optimised for 1080 and upscaling for the higher resolution monitor.

I'm looking at Lightroom through a 5K / P3 monitor on a Mac. Slide show is noticeably poorer quality.