Blockcraftery adds a variety of frames that can be replaced with most of the blocks available in the game. So if you need a stair or slab in a block that doesn’t come in those shapes then this mod can handle that!
All you need to do is place the frame and then right-click with a different block over it. You can make all sorts of changes like glass stairs:
Or any variation of slanted roofs!
This mod also requires an additional API found here.DownloadForumInstall Guide