I recently decided to try to do a big build and it just takes too long.
I really think things like pillars, floors, roof tiles, and walls could be an actual item that you must use the carpenter to craft so that they can be placed much faster. instead of placing the 102 blocks for a max length section of wall you could have it crafted by the carpenter for the discounted building cost of 2 blocks of wood (could adjust based on difficulty level, I would suggest 21 for hard mode). I imagine it doesn’t take as much wood because the walls are really hollow or something. anyway this would make building things 100 times faster, though the crafting time would probably be more than tripled, but still worth it imo, because you can stockpile building materials rather than raw materials. Think wood piles or stone piles, but with sheet-rock, and 2x4’s.
To be clear, your design in the building editor will be the same, but instead of requiring blocks it could queue up the build sections that are required, and put in place. because measurements will sometimes be odd, this means it won’t be 100% fit but even if it replaced 50% of a building with generic crafted building materials and the rest manually built block by block, this would speed things up.
Maybe include this as an alternative way to interact with the new building editor, to select pieces of the building that the game has designated as a generic chunk to maximize the use of the carpenter. Obviously some calculations would have to be done along lengths of walls and floors to figure out how many blocks we want to chunk together to create this generic crafted block. So 2x2 and 3x3 and 4x4 floor panels, 1x6 pillars, 1x2 and 1x3 shingles, 6x5 sheetrock (because doors require 5 blocks) etc.
This is actually more realistic in how buildings are put together today, because things are made in set sizes and buildings are unique, you have to figure out what fits best for your design, and this makes things come together in kind of a quirky way that could be interesting and give your buildings some charm.