https://www.oreilly.com/library/view/learn-ethereum/9781789954111/0bc452a8-d2b7-477a-b64c-bf497af4b5b1.xhtml#:~:text=A%20fallback%20function%20is%20an,match%20the%20intended%20function%20calls.
ah. no, no fallback. will consider for future versions. cc/ @ds