[plt-scheme] Need help understanding some DrScheme options

In my notes on how to use DrScheme, I had written:

Reuse existing frames when opening new files. Left unchecked, opening
or creating a new file will occur within a new IDE window. Open files
in separate tabs (not separate windows). Left unchecked, opening a
file will occur in a new window, and creating a new file will occur in
the same editor. You should check both features. It will prevent
multiple instances of DrScheme, conserving resources, and perhaps
equally as important, it will make DrScheme more fun to use."

I think this is incorrect.

The first option determines whether or not files get opened within the
same DrScheme instance.

The second option determines whether or not the file that is getting
opened replaces the existing file (within a given instance), or opens
a new tab (within a given instance).

Is that right?