Just made an account to offer my 2 cents (the game looks pretty interesting so far! I might have to try it out). Falling blocks and using support seems like it could (potentially) be really cool, though TFC's version of it could definitely be better.
This seems like it'd be a great project for modding, though it'd be awesome if it was implemented in the game. I'm not a terribly experienced programmer yet, but I do find this kind of thing fun so I might look into it if I decide to get the game and I also end up liking it.
I think a good, (though perhaps idealistic) way to do support and blocks falling is to make every block have a "support" value for how well they can support things. I don't know how plausible that'd be, I have a rough idea of how it could maybe be implemented but I have no idea how to make sure it doesn't eat up too much performance or if it's even possible with how the game is set up. Maybe with some tinkering it can be done in a realistic and fun way though!