We have an upgraded ISV solution package in LCS which we'd like to review in our sandbox. I'm looking for documentation to help initially deploy this upgrade (binary) to sandbox but also would like to see steps to move it to production if the time comes.
To be applied to a sandbox, and eventually production, you will need to make the ISV package a part of you single deployable package. There are a few ways to do this, the most common is probably still to add the binaries to source control, and use Azure DevOps build pipelines to create the single package.