How to inject into any .net application (unless AoT compiled)

Application.exe.config

<configuration>
   <runtime>
      <appDomainManagerType value="LauncherPatcher" />
      <appDomainManagerAssembly value="LauncherPatcher, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
   </runtime>  
</configuration>

LauncherPatcher.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Reflection;
using System.Threading;

class LauncherPatcher : AppDomainManager {


    public override void InitializeNewDomain(AppDomainSetup appDomainInfo)
    {
            AppDomain.CurrentDomain.AssemblyLoad += (sender, args) => {
            var name = args.LoadedAssembly.GetName().Name;
            
            // wait for relevant assemblies we want to hook into to be loaded
            switch(name)
            {
                case "Application.Library":
                  //hook here
                  break;
            }
        };
    }
}