That experiment (and other experiments) are currently on hold because the Terraform Core team is a little understaffed right now, due to some recent team departures. With our smaller team we’re having to focus on only one large project at a time. We do intend to revisit this and the other active experiments in the coming months once we’ve got some new team members on board, though.
We are still collecting the feedback folks share about it though, and so once we pick up that project again we’ll be able to make another iteration that addresses the concerns and suggestions people have sent in. For the other topic you linked to here, it’d be helpful if you could record that as a bug report in the main Terraform GitHub repository, including the details that the bug report template asks for to help us to reproduce, since what you saw seems to be (at least in part) a bug rather than an intentional design choice. I’d love to figure out what’s going on there, but to do so I’ll need to be able to reproduce the problem on my machine so I can debug it.