Note Layout Blocks
Beyond text, lists, images and tables, Notion's basic blocks include blocks that shape how a page reads: toggles and toggle headings that fold a section away, callouts that set a note apart with an icon and a tint, and columns that put blocks side by side.
Why deferred
None of them is in Tiptap's StarterKit, and each needs a custom node designed twice: once as an editor node view and once as the generateHTML output the published view sanitizes. A toggle also needs state in the published page, and columns need a drag-to-arrange interaction plus a mobile layout. That is a design and a sanitizer allowance per block. Meanwhile the writing kit, with images and tables, already covers the documents a single owner writes. Until the slash menu ships, a new block would also be one more menu-bar button.
Revisit when
The slash menu has shipped and someone asks for one of these blocks by name. That one block is proposed on its own, not the set.