When I first got my current computer system back in the summer of 2016 I upgraded from Lr4 to CC, since I also got a new 5K display with the system and needed the HiDPI support.. Back then in the Loupe view if you selected the Fit option it would fit the image to the screen as you would normally expect, but any image that did not fill the available space was limited to 1:1 magnification. I actually really liked this, since if you have Fit selected you can use the mouse wheel to scroll through the images, and you could be certain that the image you were looking at had at most been resized downwards.
Shortly afterwards at some upgrade they changed the behaviour of fit so that it did what it implies, sized the image so that it would fit the available space, even if it meant that you were looking at an image at more than 1:1. The problem is that having a lot of images from my 300D at 3072×2048px and still using my old 20D as a second body/backup at 3504×2336px these all fit well within the available area on the screen, so I now see them at sizes well above 1:1, unless I "zoom in" and specify a magnification.
Having to keep checking how big an image actually is by looking at the size info is a bit of PIA, and sometimes I wonder why I had accepted a photo, only to find that I am viewing an image at 200% or more, if it were cropped from the 300D for example.
So does anyone know if t is possible to set Lr up so that it behaves like it used to do, and limits the Fit view to a maximum of 1:1? Since moving the next image by using the mouse scroll wheel is comfortable, as is having a larger image downsized to fit. This is not so much an issue when looking at a folder when all the images are from one camera, but in a smart collection when you don't know quickly which camera was used it makes a difference.