The general / SEO tabs aren't there when editing display page templates. I can see how friendlyURL / hidden from nav menu do not apply at all to display page templates, but does everything else in "general" and "SEO" also not apply? Right now when clicking the cog for a display page template, the only field that shows up is "Robots".
all the other form fields are not useful for display page templates. The main reason is that they are automatically derived from the item being displayed