I created this as a pre-build script, but I’d like to know if there’s a better way to achieve this. The script modifies the value of disableAllRemoteConnections based on the DisableAllRemoteConnections environment variable, using a generated C# script."
Can someone help me? I would greatly appreciate any advice.
Absolutely! 
Write a small C# console application to do all this. 
Create a template .cs file and then simply call scriptContents.Replace("$PLACEHOLDER$", "actual content") to replace only what needs replacing.
This script looks like you can entirely write this in Unity as a build script. You’d merely have to toggle the config asset flag and then build.
Note: use AssetDatabase.SaveAssetIfDirty(backendConfig) to save just that file rather than calling SaveAssets (equivalent to File - Save Project).
Yes, that’s great advice, thank you!
But I need this script to run in Unity Remote Builds and they ask for this sort of build script so I can use the env variables.
Am I missing something?
So is this script working or not? Initially you just asked if there’s a “better way”. If it’s working, it’s fine. But if it isn’t working please let us know what exactly fails.
As to better way: keep this script entirely in the project. Use the batch file to only create or delete a file, perhaps name it exactly like the env variable. When the project opens, use InitializeOnLoadMethod to check File.Exists() and depending on that, you toggle the bool in the asset.
