The footprint shown on the documentation for the above part using the 36V configuration will result in a direct short of the cathode and anode to ground. The 18V configuration is correct and should be the only one used. The bottom view of the part shows 2 solid lines for the cathode and anode. So using the 18V footprint will work, but the 36V footprint will result in a direct short across the part.
Assuming that this is the document being referenced, there may be some confusion occurring; the green regions in the excerpt below represent non-conductive portions of the device footprint, rather than the reverse.
To state that the manufacturer’s suggested footprint for a 36V configuration (further below) is inherently non-viable would seem a rather bold assertion; if it is maintained that this assertion is correct, further explanation or demonstration would be in order.