The Western powers are not treating the situation as if they themselves were at war, hence no drastic changes in economic output to favor war machines. We have increased production though. Can't say how much, but it would raise eyebrows. I feel we should have been far more generous with the munitions, especially the older aircraft (think F-16, F-18) early on.
The certificates are basically just a paper trail. The aluminium is aircraft grade, the optics in spec, EMI shielding is sufficient, etc. We do extensive testing, but things slip through. Some issues are storage-related, and others are issues that don't show up til years later - such as microscopic ESD damage. Much of what we've been giving Ukraine was in storage for a while.