I have a question regarding Amex 2-4-1 vouchers and rebooking which I can't see in this thread (or I've missed - it's a long thread!).
I had a Club World flight booked to Peru next week which has now been cancelled. It was booked using Amex 2-4-1 voucher. I'm reluctant to request a refund because the 2-4-1 voucher will expire before my intended re-booking dates, even with the 6-month extension, so I'm looking at the Future Travel Voucher option which will expire in April 2022.
I understand I can request a Future Travel Voucher and all the elements of the booking are retained in that (2-4-1 voucher, cash and avios). When I later come to use the voucher to book a future flight, will I be expected to pay any extra if I book a flight on the exact same route (i.e. London-Lima). Let say if BA increase the avios required for the route, or if the taxes increase, will I need to pay the difference? Conversely, if any of these elements decrease (unlikely, I know) will the difference be refunded?
Also, if I were to use the voucher to book a flight on a different route with cheaper avios and/or taxes requirements (e.g. a short-haul in Europe), what would happen to the remaining, unused, avios and cash on the voucher?
Thanks in advance!