Question Extending HDRP\LIT with/without Shader Graph. Shader gui problems.

I just want to mix some of my color textures when using HDRP/LIT shader.

At first I tried to use Shader Graph but replicating all the Lit material features is just not an option.

Than I decided to find Lit.shader duplicate it and add my properties.

Again the problem is that by default Lit shader GUI don't display additional properties.
I can see my textures and color properties when I comment CustomEditor "Rendering.HighDefinition.LitGUI" in Lit.shader but than there is so many properties that it is not acceptable.

I went to a drastic measures and started to copy the content of
"\Library\PackageCache\com.unity.render-pipelines.high-definition@10.3.1\Editor\Material\Lit"
But i got a lot of errors "not accessible because of protection level" kind of. (A lot of stuff there is internal).

What to do, I'm actually very surprised this is not simpler.
I can imagine a lot of people would like to extend Lit material that way.

 

I too would like to know how to extend the HDRP/Lit shader directly. Sadly the documentation on writing hlsl shaders for HDRP is very underwhelming.