Okay. Got a reply.
I wasn’t right about the location. He said the reason he doesn’t ask for it is because it’s not needed. Only the address is needed.
And he also said:
“Again, everyone should sell their chometz – regardless.
“Less than a kezayis we’re mevatel.
“We also sell any chometz we may not know about (even though in truth we are mafkir that too).”