I've been curious about this mystery for some time. It "seems" that baking at higher temps do produce bigger oven springs but if it does, how does it do this? Theoretically it should not make a difference since water boils at 212F, so technically any temp above that should produce the same oven spring.
To solve this mystery, all we would have to do is a simple test. Take 2 pies from the same batch and bake them at different temps and see. For this particular test, I decided to use an emergency dough formula and bake in my MBE (mini black egg) oven. I chose this dough formula and the MBE b/c I've had the best results with it for oven spring and I can easily control the temps in the MBE.
I used a very basic NY dough recipe with just flour, water, ADY, and salt. No sugar or oil was added. ADY was at a whopping 1% and the dough was proofed and baked at about 3 hours from start to finish.
These were taken from the same batch and ended up being around 100gm each stretched out to 7". I purposefully left a thicker rim for easier comparison post bake.
The first pie (red pie) was baked at a temp of 520F. I normally bake pizza at 700 and get a good crust rise, so I decided on a much lower temp of 520 to see the difference. At the start of this test, I fully expected a difference in crust rise. My hypothesis is that a higher oven temp will indeed produce a bigger oven spring if all other factors impacting oven spring remain the same.
The first pie ended up taking around 4-5mins to bake and the bottem was still pale. The 2nd pie was loaded at a hearth temp of 700F and baked around 3 min.
The result is that a higher oven temp doesn't improve crust rise (oven spring). It does cook a pie faster though, if that's what turns you on. Visually both crust had the same amount of rise to them. The lower temp bake required more time in the oven and consequently produced a crunchier rim which I much preferred. The other rim had a slight crunch to it at first and softened up later.
I didn't care as much that I was wrong in my hypothesis but discovered in the process that baking below 700F is where I really should be baking for crunchier rims. Without this experiment, I'm not sure how many more soft rimmed pies I would have eaten.