Request a new feature, or support for a camera/lens that you would like to use in Capture One.
I like to go to the slide show mode to quickly look at my images full screen without any remaining tool bars or margins. The actual full screen mode of Capture One still retains info below and above the image that I don't want to turn off every time just for full screen viewing.
So the slide show works for full screen viewing, but there are two problems with it. First, there is always an effect applied when going from image to image, which is really annoying if I'm not actually doing a slide show. The least bad is the fade effect but it just takes too long. Should be trivial to add a "no effect" option.
The other problem is that when I flip through the images with the arrow keys, when I go out of slideshow mode again the first image is still selected. So the mode doesn't work well for choosing images because you lose your position in a large set. In principle, slide show mode (even though it's not meant for that) would be great for flipping through images, even editing them with the key-press-and-scroll quick edit feature. But the two problems mentioned get in the way.