In fact, all European airlines I have looked at charge more YQ originating North America. They throw Avios/Miles/Points at you with credit card schemes but claw it back at the other end.

Incidently though, BA do not charge more because it is not their home market, since YQ from mainland Europe is lower than from the UK. So, you may be better off getting your return redemption from mainland Europe.

The best thing here is to beat them at their own game. Unless you have a 2-4-1 to redeem, book a return from the UK or Europe with a return date far in the future then you can change when you know firm dates. a GUF could apply just as much to that return booking. There is a small change fee but it's much less than the YQ piss take.