I’m not sure if I’m following correctly, but my understanding of TipTap (as opposed to Umbraco’s implementation of it) is that it’s somewhat analogous to TinyMCE, in that Node extensions are not necessarily bound to individual command buttons, but yes, are bound to how they are activated by specific buttons e.g. If I recall correctly, the standard Table command can activate Table, Table-Cell, Table-Header, and Table-Row node-extensions. Of course, this implies that Umbraco (or a developer) creates and implements such an extension to support the required HTML Nodes.
edit: for clarity, I don’t recall that extensions necessarily requires the use of a control button (I can’t imagine a paragraph requiring it) but if it is, then you need to specify the details within the extension.