Originally Posted by
Globaliser
I don't think you need to put anything of the sort on your ESTA application. The ESTA application form asks for many details which are optional, and I think that many people overlook this.
You are correct, it doesn't need to be done, the MMB data comes up at the top of the CBP officer's screen, s/he can page down to the Esta information too. I guess if you have time on your hand you can regularly update the Esta information with the latest flight and location information, but it's by no means essential and I can't see it doing any good, or indeed any harm.
"In transit to X" is OK, I would include the onward flight number too.