I went from a shoe with a 12mm drop to one with 4mm after reading
Dr. Mark Cucuzzella's book and listening him talk about shoes on a few podcasts. I also stopped wearing insoles as a result. My training went better than past training and I have no foot pain but I've never really had much foot pain outside of injuries. I also walk barefoot as often as possible, or just in socks, to keep my foot strong.
He is a doctor and a runner and his take is that the foot is built to do what it needs to do without tons of support. Our bodies are meant to run with as close to 0 drop as possible and the arches are meant to flex under pressure. Adding stability control, insoles that keep the arch from moving, or too much padding to the foot is unnatural and perpetuates foot problems, it doesn't solve them. He uses PF as an example and says one of the first things he has his PF patients do is walk barefoot as much as possible. The only way to strengthen the foot is to use it properly.
I wouldn't make drastic changes. For mine I stopped half way at an 8mm drop for about 500 miles then moved to 4mm.