ArchitectureCraft adds in slanted blocks, railings, and other building-related blocks. Think of it as a replacement for Carpenter's Blocks with less features, while still providing the main features wanted.
For some examples on what is possible with Architecturecraft, this is all just chisel variants of cobblestone combined with Architecturecraft: https://i.redd.it/2qf3xuoau9i41.jpg
This also heavily uses Architecture Craft: https://imgur.com/a/uho9RQH
(Source for examples are reddit, First example, Second example)