I don't have an argument, I have a fact for you........Inflation is going to rise. Fact.
You seem to be fixated with inflation, it seems to have suddenly become your preferred indicator of the perils of Brexit, inflation is very much like currencies, there have undetermined tipping points when they become advantageous or not, its nearly impossible to be exact about what level is preferable.
Was sterling overpriced and just needing a readjustmenet or has low inflation just been an indicator of weak demand and so it goes on, its clear that we cannot hope for a long term collapse of our currency nor do we need hyper inflation but it seems churlish that you cite a weaker sterling and perhaps future inflationary pressures as some obvious signs of the consequence of Brexit, when current actual data shows an extremely robust UK economy.
I got told 25 years ago that low inflation is like having low cholestoral whilst dieing of malnutrition, I think I know what he meant, its a simple matter of balance, we are no way near where these indicators pose any significant threat to our future economic success associated to Brexit, it just doesnt.