Custom overrides of parts of a package

Hello!

I recall this is in the roadmap, but I couldn't find any definite info on the current status and if this is even possible in the current state of the package manager

I want to make small adjustments in the ShaderGraph package for our project. I can easily make the changes locally, but is there any system in place yet for sharing overriden packages? Or having the package read certain files from Assets rather than from the default ones inside the package, kinda redirect the paths?

We're using 2018.2.6

 

Thanks!