So 64A is now open for my flight on Tuesday.
Do I go for it (which I believe requires a call to Customer Services, yes?) or is it too much of a booted-out-by-a-baby risk?

Currently I'm in 14K, generally believed to be the fifth best seat in CW for tall pax (and not just "generally", but the clear view of that premium seating guru, Swanhunter, no less). Needless to say, 62A, 62K and 64A have not been available since the time I made the booking.