It is not optional if you require syslog over TCP. Fortigate UTM's support two types of delivery, UDP 514 and TCP using RFC3195. So yes technically it is optional if have the choice between UDP and TCP. However in our case, we do not have that choice. We have to use TCP, and Kiwi does not look to support it.
I have installed and configured winsyslog. This application does support RFC3195 and I have it working.
Thanks for the assistance.