Is the UK preparing for war amid threats of conflict?

One problem is that technology has been changing rapidly and profoundly starting from about 30 years ago.

Right now, nobody really has a clear understanding of which technologies to invest heavily in to generate an advantage in a full scale conflict. What is clear is that the current understanding of the roles of the air force, the navy, panzer, artillery and even the infantry is obsolete. (The principle danger is the failure to adequately realise that). Satellite observation and communication, drones, artificial intelligence (aka multi component systems coordinated by unifying but possibly distributed intelligences), computer algorithms and high speed computers - all of these make all conflicts fought more 15 years ago irrelevant in terms of knowledge gained and experience developed.

So maybe one does NOT want to invest too heavily in developing distributed manufacturing capability right now, because right now nobody knows what manufacturing capability will be most relevant. The important things are already been done anyway - research and decentralized state of the art manufacturing.