It’s still automatic for France as your reg is not read but one of the other countries needs a reg plate, I think it’s Spain and maybe Portugal too
Portugal certainly - Spain still has barriers on all roads I have used but in Portugal, on some roads like those around Porto, you pass through a lane with an ANPR camera so it is important to keep the reg. no updated. This is easy to do as Chrome on my phone or tablet remembers my login details so, as you say, can be done on the fly.