From the same thread as I referenced earlier, this post by corporate-wage-slave indicates you even get the deposit back! https://www.flyertalk.com/forum/29449159-post5.html

I know you forfeit the deposit after 72 hours, but it seems - I've never tried it - that if you complete the booking with 72 hours and then immediately cancel you can get it back. A loophole?

ETA: I suppose it makes sense really, after all they refund the deposit when you complete the booking, then they refund the booking when you cancel within 24 hours.