For machines with multiple warranties, it gives only first

[wrbeaudo]

If the machine has multiple warranties, the attribute being pulled is from the shortest.

This line:

LenovoInfo/1.0/LenovoInfo.psm1

Line 169 in 317f53c

$properties.Add("WarrantyEndDate", $webresponse.wiOutputForm.warrantyInfo.serviceInfo.wed[0])

should be:
$properties.Add("WarrantyEndDate", $webresponse.wiOutputForm.warrantyInfo.upmaList.upma.mEndDate)