Microsplat biome texture blending, shared height etc

Currently as far as well can tell Microsplat does not properly blend textures in biomes. so we mix them ourselves

https://media.discordapp.net/attachments/553959088707600384/878528574318055454/unknown.png?width=1076&height=702

We also can't get the top layer of biomes "flatten" or any other controls. to work as expected unless we manage the shared heightmap outselves (graph impractically large to screenie that)

Since they don't blend textures or heights usably for our "Microsplat Biomes+cities on Top" we are reduced to literally rebuilding the current biome system as functions

https://media.discordapp.net/attachments/553959088707600384/878410913189863434/unknown.png?width=1342&height=702

if you put all this together in terms of "usability" it makes actually using biomes in a games incredibly difficult unless you just "throw things on top afterwards" which is not ideal.

To solve it I did a longhand version and it does work as expected but honestly I could do this with like 10 controls if MS blending "just worked" as expected and the heightmap controls (Like Flatten) respected the underlying height layers.

I will revisit the texture stuff. maybe I missed something but I wasn't the first to say it wasn't working as expected. It seemed to choose the wrong colors, only from a single texture channel.

The heightmap is the prority since everyone uses that. Microsplat is a secondary concern.

Would dearly love to use the single biome control version that I built a month ago over this enormous workaround.