Bouncing this thread as I just became aware of Touchless ID. SAN, my home town airport, isn't participating yet. Hopefully it will - and in the mean time, I might be returning from a participating airport.

TSA PreCheck Touchless ID participating airlines and locations:

Alaska Airlines (ATL, DCA, DEN, LAX, PDX, SEA, SLC)

American Airlines (ATL, DCA, DEN, DFW, EWR, LAS, LGA, PDX, SEA, SLC)

Delta Air Lines (ATL, DCA, DEN, DTW, EWR, JFK, LAS, LAX, LGA, PDX, SEA, SLC)

Southwest Airlines (ATL, DEN, LGA, PDX, SEA, SLC)

United Airlines (ATL, DCA, DEN, EWR, LAS, LAX, LGA, ORD, PDX, SEA, SFO, SLC)

Eligibility and enrollment

• TSA PreCheck membership: You must be an enrolled member.
• Passport: You need a valid U.S. passport with its information stored in your airline profile.
• Participating airline: You must be flying with a participating airline and have your frequent flyer account information with them, which includes your passport and Known Traveler Number (KTN).
• Opt-in: You must voluntarily opt in to the program through your airline's website or app, and ensure the "Touchless ID" icon appears on your digital boarding pass before you go to the airport.

I was able to quickly sign up on Alaska. I could manually input my passport number and already knew my Trusted Traveler number. I haven't yet enrolled on UA. It requires scanning my passport in their app. I'll work on that later.

TSA announcement: https://www.tsa.gov/touchless-id