Posting from the Rebublic of Ireland now, as a tourist from the Schengen zone. UK requests a passport, but the Rebublic does not. So we flew in with ID cards only then drove into UK not having passports and this is explicitly allowed. Border crossing doesn't feel like border crossing at all. A small sign and a change of road sign is all. Suddenly the speed is signaled differently (mph vs. km/h). Even the driving culture is the same: speedy but careful and respectful.
In other words, this agreement seemed to have survived Brexit.
In other words, this agreement seemed to have survived Brexit.