The Commission’s note on what the UK has to do to implement the Ireland/Northern Ireland Protocol, published today, is worth a good look. ec.europa.eu/info/sites/inf…
On customs 
On VAT
On State aid
On what NI business needs to prepare for
The Commission was prepared to collude in what I called Agatha Christie drafting, to help the UK Govt to get the Protocol through.
But another (more highbrow) metaphor is the Faustian pact. It works for a while. But then you find that the other party starts being distressingly clear about what you have signed up to.
(And note that on customs the Commission has abandoned the sham that non-payment of EU duties on GB exports to NI is the rule, when it is absolutely clear that it is a tightly confined exception.)
(And also note the now blunt insistence on the carefully disguised reality of Art 10: even after transition, the UK remains bound by EU State aid rules and has to apply and accept Commission decisions.)
