Lithium 0.12.5 is the first release for 1.21. It includes several new optimizations. For now, some new optimizations are disabled by default, because mod compatibility issues still need to be resolved. Check https://github.com/CaffeineMC/lithium-fabric/blob/mc1.21-0.12.5/lithium-mixin-config.md for a description of each optimization and how to disable them if any issues arise.
## Additions
— new: optimized explosion entity exposure (thanks to RacoonDog)
— new: general raycast optimization
— new: empty space search optimization for entity positioning when using nether portal
— new: disable useless nearest item sensor in goats
— new: skip sprinting particle creation logic used by all mobs on server side
— new: fluid flow (nearest hole search) optimization
— new: skip ticking mob equipment when there aren’t any tickable enchantments (only soul speed)
— new: avoid creating and dispatching game events (vibrations) to sections without any listeners
— new: skip accessing chunks when trying to dispatch game events
## Changes
— change: vanilla’s supporting block used for additional entity movement fast- path
— change: track mob equipment using the item stack listening system to optimize checking whether updates must be sent
— change: enable block entity supporting block caching by default
## Bugfixes
— fix: wolf armor not updating visually
— fix: use correct entity box for world border collision check
— fix: neighbor path node types initialized to OPEN, allowing mobs to pathfind directly next to dangerous blocks
