How does Windows.System.Configuration.Install.Installer work - windows

Question

I am trying to configure my installer so that it will close any instances of the application before installation starts and relaunch the application once installation has finished.
The MS documents provide and example similar to the one below and indicate that the [RunInstaller(true)] annotation specifies whether the Visual Studio Custom Action Installer or the Installutil.exe (Installer Tool) should be invoked when the assembly is installed.
Of course this could mean just about anything...
I am using the Visual Studio Project Installer NuGet package to create the install files (setup.exe and APP.msi files). When configuring the Project Installer there is an option set configure the Custom Actions - I assume this is what the documentation means.
However the Custom Actions has options to add things to the Install, Commit sections - what has to be added to these sections and how does this relate to the Installer class defined below.
This whole area of installation seems to be poorly documented and there seem to be so many options, none of which seem to work properly.
You would think closing any running instances before installing an update and then relaunching after completing the installation would be a no brainer but it seems anything but simple.
Appreciate any assistance with a working example of how this can be achieved.
namespace FocusBracketer
{
[RunInstaller(true)]
public partial class Installer: System.Configuration.Install.Installer
{
public Installer() : base()
{
InitializeComponent();
// Attach the 'BeforeInstall' event.
this.BeforeInstall += new InstallEventHandler(Installer_BeforeInstall);
// Attach the 'Committed' event.
this.Committed += new InstallEventHandler(Installer_Committed);
// Attach the 'Committing' event.
this.Committing += new InstallEventHandler(Installer_Committing);
}
// Event handler for 'BeforeInstall' event.
private void Installer_BeforeInstall(object sender, InstallEventArgs e)
{
Console.WriteLine("");
Console.WriteLine("BeforeInstall Event occurred.");
Console.WriteLine("");
}
// Event handler for 'AfterInstall' event.
private void Installer_AfterInstall(object sender, InstallEventArgs e)
{
Console.WriteLine("");
Console.WriteLine("AfterInstall Event occurred.");
Console.WriteLine("");
System.Diagnostics.Process.Start(System.IO.Path.GetDirectoryName(this.Context.Parameters["AssemblyPath"]) + #"\FocusBracketer.exe");
}
// Event handler for 'Committing' event.
private void Installer_Committing(object sender, InstallEventArgs e)
{
Console.WriteLine("");
Console.WriteLine("Committing Event occurred.");
Console.WriteLine("");
}
// Event handler for 'Committed' event.
private void Installer_Committed(object sender, InstallEventArgs e)
{
Console.WriteLine("");
Console.WriteLine("Committed Event occurred.");
Console.WriteLine("");
}
// Override the 'Install' method.
public override void Install(IDictionary savedState)
{
base.Install(savedState);
}
// Override the 'Commit' method.
public override void Commit(IDictionary savedState)
{
base.Commit(savedState);
}
// Override the 'Rollback' method.
public override void Rollback(IDictionary savedState)
{
base.Rollback(savedState);
}
public static void Main()
{
Console.WriteLine("Usage : installutil.exe Installer.exe ");
}
}
}