Higher Lightmap Resolution on Terrain

In our game we have big terrains of around 1000x1000. However the lightmap size limit is 4096 causing blurry shadows on the terrain. Is Unity thinking of splitting up terrains somehow so we can have higher lightmap resolution for terrains?

 

So far that seem not to be an option.
You could split the terrain yourself and to get 4 times the resolution (or more if you split it into more then 4 pieces)
I found this post with a script for splitting the terrain ( not tested)
https://forum.unity.com/threads/split-big-terrain-into-smaller-terrains.140645/#post-3219379

I agree that an option for 8k lightmap texture would be nice.

For terrains i often have seen that he baked shadows are only used for the distance shadow rendering and Realtime light for the near distance high quality. But that strongly depends on your usecase.
https://docs.unity3d.com/Manual/LightMode-Mixed-Shadowmask.html

 

I've faced this issue too and ended up splitting the terrain into smaller pieces, however it introduced another issue. The terrain tiles have visible seams and the baked light behaves weird on the terrain.
https://ibb.co/mh96Zb9