Fix map in itemframes lag
Enable Improved ping sending
Metrics is not severe
Fix livingentity collision reduction
Timings improvements
Entity Activation Range

This feature gives 3 new configurable ranges that if an entity of the matching type is outside of this radius of any player, will tick at 5% of its normal rate.

This will drastically cut down on tick timings for entities that are not in range of a user to actually be "used".
This change can have dramatic impact on gameplay if configured too low. Balance according to your servers desired gameplay.
Reduce Entity Tracking Ranges

This will make players not track entities as far as they usually do.
This has multiple benefits:

1) Less bandwidth. Not sending update packets for entities that are not even close to a player, and in many cases, not even visible.
2) Less lag by maps in item frames - Default range is 160 blocks... Many players can track that item frame and cause lag and not even see it.
3) Less client lag - Not trying to render distant item frames and paintings and entities will reduce entity count on the client, which is major for shop/town worlds which may use tons of item frames.