When templateData is unavailable, the wizard provides "guessed" parameters based on the template code. The guessed parameters may have within them aliases that are almost the same parameter name, with spaces or underscores interchanged.
When TemplateWizard guesses parameters, it should ignore (not display) repeated parameters like these.
However, this should only happen during the "guessing" part. If TemplateData information exists with multiple params, they should all show, since we assume saved TemplateData blobs know better.
Here's an example I saw in TemplateData editor parameter guess