whatever happens you are going to be faced with very long ques because each passport has to be examined and stamped. you cannot use the electronic barrier and in the old days when they were reading a magazine or something and just waved you through now they have to take your passport scan it and then stamp. this also applies when you leave to go back to UK passport has to be stamped in and out so ques both ways. Plus at the moment on entry examine covid test and QR code from Spanish health web site . it is bad enough now and nobody is traveling so when all the planes come in I recommend you have a good book to read as you wait . dont expect them to rush

The good news is it will all be worth it to spend some time in paradise