Here is the answer… All the way at the bottom of this document
https://www.netfilter.org/documentation/HOWTO/NAT-HOWTO-10.html
Works like a charm !
For windows routing, if you have only configured your full tunnel exit point for ip4 then go into the windows control panel, network settings, change network adaptor properties and disable ip6 physically in the adaptor settings of the NIC you connect to your Internet with.
Set the zerotier app settings to the following
As soon as I did that, everything works. https://ifconfig.co states my exit nodes ip address and port forwarding through my exit node works.
Hope this helps someone.