Issue: On AEM 6.4.. When trying to refer an Experience Fragment inside an "Experience Fragment Component" on a sites/page, the "experience fragments without any "cq:xfVariantType" property do not show up. The Experience fragment functions normal.
As of now we have added this via code but there is not way to add this property to the "editable template" other than via crx/de. And which is not a way we can recommend to customers while building editable templates.