what happens when you cancel the tickets - do you get the funds back on the card or does WN keep it as a deposit in your funds wallet or do they keep individual ticket credits for flights?
Here is what I understand

First set Amex airline to WN in Jan
Option 1
Buy a cheap 99$ fare - wait 2 -3 days for credit from Amex
Cancel fare on WN- get travel funds on WN valid for 1 yr
Issues - fare expires 1 yr from purchase of original ticket
So if I have 3 cards in family - get the ticket 30 days before annual fee hits for each card

Option 2 - do it all now
Find a cheap anytime fare below $100
get amex credit
cancel later - get funds back to card and get money back from Amex

Either way a lot of work but free cash is free - especially if your time is worthless
:-)
Any corrections welcome