It seems like our output needs trimming. Using an -eq against the formatted output of many of the commands will not work properly without a trim...
Example
DOESN'T WORK!: $LogonPasswords = Get-MKLogonPassword | Where-Object { $_.UserName -eq $TargetUserName
DOES WORK!: $LogonPasswords = Get-MKLogonPassword | Where-Object { $_.UserName.Trim() -eq $TargetUserName
}
This isn't horrible but can be frustrating - should clean this up.