Yet another mad letter from someone who knows nothing about export/import procedures. Another fool who would not last two minutes filing necessary pieces of paper at Dover!
In passing, I have had some experience of 'just in time' deliveries with my children.
I tend to like their birthday presents to be delivered 'just in time' so that do not have to store them, clogging up their bedroom with large parcels, in the days leading up to their birthday. This involves me finding out how long they will take to deliver and posting on an appropriate date.
At Christmas for some reason I find that my supply-chain tends to take longer but cunningly I post a little earlier to take this into account. I wonder if this might go some way to providing a solution to manufacturers post-Brexit i.e. if it's going to take longer to get there, send it off earlier?