Originally Posted by Kimomo

I don't suggest you try your luck. It seems WA intends to leave individual nights only, not 5 nights in a row. Even you see 5 continuous individual nights is available, sometimes you still can't book it as 4+1 nights since they release it as a different room type.
My booking experience is also bad, it's better you have enough 480k to test the 4+1 nights is bookable or not. Don't just trust the flexible date inventory you saw.
I also try to cancel one extra point night trying to replace it with certificate, but inventory never come back. I wait like 3 months until the inventory shows up again, I believe it's not due to my previous cancellation.
Cancel your point night will need 24~48hrs to go back your account, for my own test for one WA point night, it took 48hrs to refund but the activity didn't see any 120k refund. It just add back to your total point, therefore make sure you record your prior total point before you cancel a point night.
Even you are lucky the inventory goes back after you cancel, your point will take 24~48hrs to refund. You might pray inventory will not disappear during this time. Therefore I suggest to make your travel plan flexible, book any preferred & available 4+1 nights first and make the change later.