I disagree heavily here. That proposal’s goal is to alter ADTs, which are a fundamental part of the language, into something quite outlandish with far-reaching implications. It wouldn’t even solve the issue I have, since binding that monstrocity to an existing chunk of memory would be impossible.
Using mutable things unsafely across threads is a design decision that users can already make. This proposal would merely allow people to use mutable things as records, that’s it.