I see you have bought into the Barnier bullshit. WTO rules will apply; the Germans and other net exporters are already looking for side deals under the famous Brussels back room “exception” diplomacy.
WTO rules will apply - and that will kill
1. British manufacturing which requires no borders as it consists of a number of parts or half-completed products moving across the borders — think if California had trade borders with other states - or more accurately if Ohio or Illinois had it
2. British financial services needs the open borders
3. Germany 9.81% of all british exports head to Germany.
in contrast only 6.21% of all German exports head to the UK