CA changed the schedule of the 10 minute earlier departure from Chendgu to Lhasa to 40 minutes earlier, so I refunded my partner's UA frequent flyer ticket. CA had put up heavily discounted first class fares, so I bought one for my partner on the same flight as I'm on, from Travelzen. It ticketed instantly, so that answers the question of whether Travelzen will ticket flights to Lhasa.