The danger is we will have absolutely no say in anything does for those 21 months. May has given all our leverage away. This implications are becoming clearer with each day that passes. The idea that things will continues as was during this interregnum is naive and laughable. Decisions will be made by the EU in that period that will impact adversely our country for many years post Dec 2020.
Fishing rights are one example. We simple cannot believe Mrs May will stand by her commitments to the British people and she has already reneged on so many. Despite her statements to the contrary she will bargain away fishermen's livelihood and communities to save the Bankers of the City of London. The longer things drag on with us not out of the EU the greater will be the danger to our country and way of life.
Another example is the EU Galileo GPS system requiring huge investment to compete with the existing functioning US system we all currently use.As an example of how long it takes the EU to do anything it cannot be rivalled. I was at a meeting in Brussels in 1978 where it was discussed. I heretically asked what was the point of this system when we could use the existing, working US system as we do today on our Sat Nav. The bien pensants fell upon me as an unbeliever. We must have European not US solutions to European problems was the predictable French response. I simply pointed out that the \G in GPS stood for Global ie covering Europe. I was not invited back.
UK companies however now to be frozen out of the development of this system and I am sure this scenario will. be being repeated over the EU procurement process.
We may run an open and blind procurement process for printing our passports. How many other countries do?
It is hopelessly naive to believe that during the implementation period we will get a fair crack of the whip from the EU with things continuing as before. We will get royally screwed by the EU. Mrs May will just have to lie back and enjoy it.
Get out of his silly dangerous transition deal and go to WTO rules on 30th March 2019 ignoring what the French boss of WTO says.