Yep, this is mostly helpful to those whose 10 year green cards are expiring. Those who have 2 year GC with pending I-751, already have 48 month extension letters which supercede 24 month extension from N-400.
Sure, if they are interested in listening to you and allow you to defend your case. Sometimes they come to conclusion and aren't giving any opportunity to clarify things. Carrying proofs can help
Wonder how many of VJ users only have one citizenship VS how many have dual citizenship from birth / naturalization VS how many have duel citizenship from birth / neutralization
Those folks even ask for stamps in their British passports when landing in the UK. They ask for after exiting through e-Gates. I'd never go through such hassle.