It sure would be easier for one person to stay a few extra days now. That's my guess. But then, I hate airplanes.
Yes, this is typically what we do at work when we travel. We buy re bookable tickets (more expensive) and plan for a stay and very commonly there is a change of plan and we need to stay longer.
We'll see what the guys will do but I don't consider a delayed retest as a big hurdle if the test have good enough COP for a couple of hours. I will not consider it a proof that it work though I would be curious enough
to donate a few bucks for a retest and relax and enjoy life meanwhile.