Solved (hopefully). After install of new battery and alternator, it was still not right. The tech examined connections and did find a loose connection from junction box to alternator. This was intermittently faulty as the engine vibrated. Unclear if this perhaps damaged the first alternator. I took delivery of the vehicle with a new battery and alternator. No charge, of course. No issues over the past 12 hours.
Thank you to Camelback Toyota.