Duplicate User Form in Excel VBA

Temporarily change the form name, export it, change the name back, then import the UserForm file. That way they do not match.

Another method:
With your desired workbook open...
Create a new workbook (Ctrl+N) (by default called Book1) then
within the VBA Project window (Ctrl+R),
drag the form you want, and
drop it onto the new workbook VBAProject(Book1). (a small "plus" under the cursor indicates you're doing it right.)
Now Doubleclick the form you just created. (You may need to click the "plus" in front of the Forms folder to display it) and then
in the Properties window (F4) change the "Name" to something unique.
Now back in the VBA Project window
drag and drop this new form back to your original VBAProject.
Done.

For multiple forms repeat the last 2 steps.