Products with Same origin and different batches in same location
I assume you mean that batches of different items from the UK can be stored in the same location (else you could just disallow mixed items).
I cannot think of an automatic way to handle this (i.e. nothing as easy as turning off mixed batches). You could designate certain locations to certain countries (e.g. via additional zones) and, using Country of origin on the item, configure your Put away location directives to put UK items in to UK locations. But I appreciate that the maintenance of assigning locations to countries might makes this solution too much effort to accept.