If you search for GDPR IP address you'll get 100 different opinions on what you need to do. That in my opinion is what makes this law ridiculous. How can companies be expected to comply with something this unclear? I'm sure I would have had your opinion before I was the person who is ultimately responsible if my answer to GDPR compliance is wrong.
Everyone having issues with this is somewhere in the line of fire for a wrong answer to any of these questions. Our concern over the fuzziness of this law is very valid, I don't like uncertainty personally.
If they ultimately disagree with your judgments, they will tell you, and you'll have plenty of time to get a common understanding.
They will certainly not fine you just because you made a honest mistake.
They will maybe fine you if all you have to show is "I didn't want to find a plausible way myself, nobody spoon-fed me, it's not my fault".