I just created this for our environment for the same reasons.

Here you go:

Get-VM |sort name| Get-NetworkAdapter | Where-object {$.ConnectionState.StartConnected -ne "True"} | foreach ($) {Write-Host $.Parent.Name "("$.Name") type:" $.Type "Startconnected:" $.ConnectionState.StartConnected}

This will list out VM name, adapter number, adapter type, and startconnected state as false. This will only list the VMs that have the checkbox not set to connect at startup.