ProfRB

Covid permitting, I'll be taking at least three trips to/from PIT/HKG over the next 8 months, with the first trip departing in early-to-mid August. Any advice on when I should book the flights -- should I book now, or wait until more capacity comes online? Should I use GUCs on early flights or late flights? Is there anything else I should be thinking of at this point, apart from the obvious health precautions?

BenA

There's very little reason not to book now, given Delta's current change fee waiver on tickets booked this month - if a better fare appears in the future or your plans change, you can always change your ticket without penalty.

Applying GUCs upfront is a mixed bag. They're likely to clear, but you will likely struggle to get them back if you need to change the ticket. I'd probably determine which of your trips is most likely to happen and plan to use them there.

Keep in mind that GUCs are only eligible on specific KE fare classes that are highly unlikely to show up right now, so you'll probably be in the back for ICN-HKG no matter what.

MSPeconomist

I'd at least wait to see how the Hong Kong entry and quarantine requirements evolve. IIRC it's currently the case that most people who aren't already Hong Kong residents or citizens cannot enter currently and, with few exceptions, everyone who enters is subject to COVID-19 testing followed by mandatory quarantine. Moreover, the routing can matter in that the requirements can differ depending on your transit airports and the countries you've visited in the last fourteen days.

As the travel date for your first trip approaches, you might find that it makes sense to use nonSkyTeam airlines in order to take a nonstop from the somewhere in the USA to Hong Kong (IIRC, currently CX from LAX and possibly UA from the west coast) in order to avoid even airside transit through a third country and the resulting difficulties.