Does cmd.exe write to stdout/stderr? - windows

Question

This is a weird question based on bad VBScript behavior that I am trying to work around. Please bear with me and thank you in advance.
In VBScript, you can do the following to start a task:
Set WshShell = CreateObject("WScript.Shell")
Set WshShellExec = WshShell.Exec(strCommand)
Do While WshShellExec.Status <> WshFinished
WScript.Sleep(1000)
Loop
However, there is a bug where, if the command/task started by the WshShell.Exec call writes >=4kb to either StdOut or StdErr, WshShellExec.Status will never be equal to WshFinished (1). I assume this is because there is no space in a buffer the system uses for stdout/stderr, so the initiated task hangs on the next write to stdout/stderr once it writes enough bytes to the buffer(s).
Depending on the program running, you may be able to do something like the following to get around it:
Set wshShellExec = WshShell.Exec(cmd)
Set objStdOut = wshShellExec.StdOut
Set objStdErr = wshShellExec.StdErr
Do Until objStdOut.AtEndOfStream
standardout = standardout & objStdOut.ReadLine & vbCrlf
Loop
Do Until objStdErr.AtEndOfStream
errtext = errtext & objStdErr.ReadLine & vbCrlf
Loop
However, this does not always work. If the running program writes 4kb to stderr before writing anything to stdout, this code hangs on the evaluation of objStdOut.AtEndOfStream or on objStdOut.ReadLine (note, you cannot use objStdOut.ReadAll because that will also block forever).
So, I've come up with the following solution that seems to work:
strCommand = "c:\Windows\System32\cmd.exe /C StdOutTester.exe > " & rsltTextFile & " 2>&1 || call echo %^errorLevel% > " & rsltErrCodeFile
Set WshShellExec = WshShell.Exec(strCommand)
Do While WshShellExec.Status <> WshFinished
Wscript.Sleep(1000)
secCount = secCount+1
If secCount >= 10 Then 'kill children
If KillTaskChildren(WshShellExec.ProcessID) <> 0 Then
WScript.Echo "WMI Terminate Failed. Killing CMD..."
WshShellExec.Terminate
End If
End If
Loop
What this does is run the actual task in another cmd window and redirect both stdout/stderr into a file (and also the error code if applicable). Because I'm running the command in another cmd window, stdout and stderr are decoupled from the WshShellExec object. This also allows me to kill the running task for a timeout (the real one, i.e. not the cmd window but the actual task, by using WMI).
So, my question becomes this:
Since I am running another cmd.exe window, it is possible that cmd prompt itself runs into the same issue if it writes enough data into stdout/stderr (in which case, my timeout logic should kill it)? Does it ever actually write anything into stdout/stderr? What about if I use the /Q option?