Not sure if it has been suggested yet, but I think gem doors would be a good addition to the interactive blocks. Probably room for plain, stylish and ornate variations. Each using compact, refined and deco gems respectively.
Glass doors would be great! We have a lot of options when it comes to ancient builds, naturalistic builds, futuristic builds, steampunk, cyberpunk, fantasy - but not a lot of options when it comes to modern builds.
Better glass was top of my list - and we got that. It’s outstanding and has reinvigorated me to try out some new things.
More doors will always be welcome, but right now I’m hoping they fill in some of the gaps - such as metal and gleam shelving.
I think the reason given for this not happening is that a 1 wide door, open or close only occupies one block. They would have to make some bigger changes to allow for a block that moved through 9 blocks.