That does not seem to be too different from having a visible, readable ID plate - the information spread is "individual at that reader at that time" (though yes

That does not seem to be too different from having a visible, readable ID plate - the information spread is "individual at that reader at that time" (though yes, if unneeded it should not be there). The issue is with more with recordings and with the principle of sending data around beyond the ID - and especially with the contract that would make such activity accepted.