Litematica EasyPlaceFixPlus

Placement from Litematica can set blocks in the wrong state, for example a slab in the wrong half, a stair facing the wrong way or a door hinged on the wrong side. This mod checks each placement before it is sent and adjusts it to match the schematic. It covers slabs, stairs, logs and pillars, chains, buttons, levers, bells, grindstones, doors, trapdoors, fence gates, rails including turns and slopes, detector and activator rails, and double chests. Furnaces, dispensers, droppers, hoppers, observers and barrels are also handled, along with blocks that can only be placed once their neighbor exists.

The mod finishes a placement with one click, using the item the player is already holding, and can be used anywhere in the schematic area. A speed slider sets how many blocks are placed per second, with a default of 10. Two options cover servers that dislike the mod: one stops it from turning the player's view, and the other sends plain, honest clicks instead. Litematica EasyPlaceFixPlus requires Fabric API, Litematica and MaLiLib, is published for Fabric only, and runs only on the player's client, so the server needs no copy. Its files cover 1.21.11, 26.2 and 26.3, and the code is under the MIT License but is not open source.