I would add that (at least in my experience) the cancellation within 24 hours after booking (which, as noted above, is without cost) only seems to be realizable by telephone. Or at least in my cases, when I go to do it online, I get an error message and am told to ring up.

So if I'm to understand the OP's initial question, which is if he can just keep making and canceling and making bookings every <24hrs, then it seems it should be possible, but would involve a lot of time on the phone.

I can also speak from experience that even on an redemption booking (longhaul F) I wanted to shift by a couple of hours, when I rang up approx 24 1/2 hours after booking (availability changed in the meantime) they collected the fee even as a Gold. So there doesn't seem to be much leeway. Agent even talked about telephone booking charge until I asked if they'd started imposing those on Golds on top of everything else.