Borders are about land, it makes sense to have clarity of laws
The modern border is absurd though. Applying it to living things is batshit crazy
People live where they live, they always have. If you integrate successfully, you definitionally live in a place. You can't be removed without causing harm, both to you and to society. Just like a deer or a tree, it's crazy to turn it into a matter of paperwork
I think we should go back to the rule of a year and a day. If you manage to live somewhere for a year without anyone noticing, permanent residency should be granted automatically as a measure of the state simply acknowledging reality