
If you are using Windows.
A workaround I used while Beta testing was to have a 2nd user profile on my machine, I installed KS8 on that user, but didn't allow it to be available for all users. When I wanted to use KS8 specifically, I would use that profile. If I wanted to use 7, I logged into the other profile.
Not the most elegant, but it did a good job of keeping them separated (very key when beta testing).