The waiver being talked about here:
https://mobile.twitter.com/CharlieElphicke/status/1237109744785031170, is to do with safety and security declarations. Now, Transit declarations double as S&S ones anyway, so that's another jolly good reason to move goods under Transit. No waiver + no Transit = a requirement to tell t'other side what's heading their way, 2 hours in advance of departure; not good.
I do worry from time to time that he isn't quite all there.