They can't implement more saves because the save archive format they are using is only supposed to contain about 5 saves (they are already breaking this limit with 40). That's why my modded version saves aren't compatible with the main game; I had to change the file archive format to up the number of saves.
Windows 10 pro makes no difference (I'm running pro). Try pasting the path directly into your file explorer directory bar.
If you try to navigate to it directly, you won't be able to because appdata is a hidden folder. To see it, you need to allow file explorer to show hidden files. See this
You must be registered to see the links
for how to do this. Then you should be able to see the appdata folder and navigate into it.