Sadly I predict that many more such situations will arise in the future, not just in the art world, as the appalling results of the ignorance of negotiators in each field become visible. The Northern Ireland border and Scottish fishing being two others that come to mind.
Before the introduction of ARR, Great Britain was the world leader in art. Unfortunately this is no longer the case. The so-called expert negotiators have moved on and no longer care. The abolition of the ARR is a must.