The UK isn't much of a primary manufacturer (raw materials) What's left of our manufacturing base is secondary manufacturing - making things, not materials basically. Those raw materials need to be shipped in from somewhere so while a low GBP may help exports, it adds to the costs of the raw materials used to make what we export which will impact margins.
Fun fact of the day - cars produced in the UK contain only 44% of UK made content, the rest is imported. Most trade agreements require >50% of a product to be made in country for preferential trade deals to apply. UK manufactured Nissans and Hondas would not be regarded as UK made. Some canny trade negotiations would be required here.
Source - Society of Motor Manufacturers and Traders
https://www.smmt.co.uk/wp-content/up...ew-Figures.pdf