+1 for an option to open each project in it’s last saved state.
Cubase does have a preference option to open your project using the last view saved on your computer. It’s not “per project” though. Again, it is the last view saved on your computer. This gets confusing when working multiple projects as the next project you open is opened using the view used when saving the last project. What the??? 
Regardless… the option(s) available to set the “Open Projects in Last Used View” are found in the Cubase File>Preferences>General menu. Description is found in the operation manual on page 1104.
If you are working and saving only one project at a time then setting the option to “Always” will do what you want.
Maybe you could change the title of your request to add the word … “Each” Project File. 
Regards 