Originally Posted by
SK AAR
No first hand experience, but I doubt border police/authorities will start stamping passports for the convenience of passengers (unless of course they stamp passports as a matter of routine or are obliged to do it).
A UK passport might very well get stamped on the Romanian border post-Brexit, but I guess one should actually enter the country on that passport - flashing an EU passport first than shoving an UK passport at the officer with a "stamp please" will probably not work.