I enjoy my job, but my boss makes everything more complicated than it needs to be. Whether it's policy, planning, implementation or improvements, he tries to "outsmart" simple things and make them needlessly complex. For example, I am the only one on the team with previous experience in a specific system, and he asked me to implement it here, too. It's pretty simple stuff, but he keeps saying "We need System X to also do 123, make it do 123. Also, it has to be able to do HIJ. By the way did you get it working with 789?" Not only are those things completely outside the scope of the system, they're things it isn't designed to handle and, in all my Googling, it appears no one else has ever demanded it also do these things. I tried explaining that these kinds of requirements are really not suitable, so he started coming up with a ton of complicated hoops we could jump through just to satiate these arbitrary ideas, talking about deploying more new systems, involving other teams, tons of work just because he decided it needs to be extended in the wrong direction.
Or later, we tried to set priority for different projects on our list. When we agreed to a one hour meeting, it was just to establish a 1, 2, 3 style list. Instead he spent four hours explaining how to visualize priority as a three-dimensional matrix along three axes, defining each axis, then disregarding those definitions in order to place everything at the highest priority, then deciding we need to use a different program to track priority, then Googling around for that, and so on. We were just supposed to make a list! And later he started talking about how there are actually six factors we need to account for when prioritizing projects...
How can I respectfully ask my boss to rein it in, and stop trying to make everything so much more complicated than it needs to be?