It is not the EU who made promises (and paid a lot of money too) to NI- like Johnson saying there would be NO paper work, etc, and that if anyone had any to fill, to just put it in the paper basket, or send them to him and he would bin them, etc. And in the context of vaccines and the EU, Johnson was the one to first mention triggering art 16, not the EU.
Many of us warned, again and again, that the border issue between the UK/NI and the Ireland/EU- was not possible to solve, and that it would lead to unbearable friction between UK- NI- and Ireland/EU - and as per usual, the repeated reply was 'ahaha project fear'.
It has not been solved, and there is NO solution- and it will create unberable friction- especially in a crisis- as per Covid.