I have an article in here on the UK and gravity in trade (trading more with neighbours). Technology is changing trade but gravity seems to hold in general. The UK is already an outlier though in our services strength, but do we want to encourage this further in our trade policy?
Put more barriers in place to UK-EU trade and the chances are you comparatively weaken UK manufacturing in the regions we are supposed to be 'levelling up'. Focus more on services and regional disparities potentially grow, plus FTAs probably aren't the answer.
The UK economy after Brexit and the impact of trade policy on this should be but isn't currently the subject of serious discussion around Westminster and beyond. Too much ideology and seeking to retro fit solutions to that. Here's a clip of the article anyway... 
cc in particular @BimAfolami who asked me the question on gravity and UK trade a few months ago. Sorry about the delay...
