Great thread. A couple of thoughts - we transited up in July of 2020. Some thoughts from our experience:
US Customs has nothing to do with quarantining requirements. That is at the discretion of the state, and in Alaska, it's being handled by harbor masters when boats are entering the state.
To clear US Customs you do not need to go to Ketchikan, and they would prefer you do not. They will request you use the ROAM App for clearing. You can do it by phone from Dixon Entrance, then as far as customs is concerned, you are done.
At least in 2020 they allowed your transit time to count toward your 14 day quarantine time. We came up in 5 travel days from Washington. We then spent the next week playing around in Misty Fjords before arriving in Ketchikan. We checked in and were free to go.
Currently, to enter Alaska, you must have a negative Covid19 test, either 3 days before departure or when you arrive. Since we stayed in Alaska for the winter cruising and have not come across any cruisers who recently arrived, I don't know how they are handling this testing requirement currently.
Looks like there is a lot of pent up demand to come on up in 2021. We spent the last summer up here with very few other boats around - almost all anchorages where by ourselves. Of course, if you really want to be by yourself, just stay up and spend the winter cruising.
Wishing everyone "no wind and flat seas".
Jim and Rosy
M/V Sea Venture