Question How to use Unity's terrain system with a compressed splat map?

Hi,
For reasons of storage space and memory use, I would like to use Unity's terrain but with a compressed splat map.

For a WebGL game with a terrain of 2048 texture res, that's a 21.3mb texture for each terrain that has a 2048 splatmap. That's a lot of data to store for a web game, plus a lot of data to be stored in memory.

Is there some way to store the splatmap as a compressed texture? Even if the quality suffers a bit, it could be worth it.

Would I need to create my own entire terrain system just to do this? Or how could I?

 

This seems to be a somewhat common request. Saving 4x the memory per splatmap (assuming it doesn't need to change at runtime) would certainly be very helpful.