I went and set up the seats on the ANA site.
They have a weird setup, you select seats and you have to register and save, so I did that for 3 segments. Then they invite you to register and save your email and passport number. I did that but didn't create an ANA FF account as far as I know.
But they knew my UA FF number, based on the ticket number and name I gave them, as well as my KTN.
They also had their own confirmation number.
I looked at some old threads, people raving about the NH soft product. It's been a long time since I flew ANA, only did it once but could have chosen UA for the TPAC, chose ANA for outbound, UA for return.
But those ANA 787 cabin layouts are weird. I went for the A and K seats. I guess their Room cabins are only on 777s?
They offer a ton of special meal options so I chose low-salt for just one of the segments. The other ones I'll just choose on board.