legacy mode breaks any page tempates in the child theme (they never load...

.../are redirected to use the legacy-page.php)

To continue our twitter convo: I would agree that I don't like the checkbox for legacy mode... and I definitely didn't like that it was automatically on, but maybe that's b/c it just drove me crazy for the last 3 hours. 

I prefer `add_theme_support()` even if that is maybe a touch harder for total non-coders.