Earlier I was playing the game on my PS4 slim, digital edition.

I was messing about in photo mode in the 'Time To Rally' mission, when I found something interesting - when using photo mode slightly before & after regaining control of Miles after he slingshots off of the crane on his way to Braithwaite bridge, I gained a considerable amount of speed and height.

I was able to recreate it a few times, once to the same/slight better extent, and some worse. It might be timing based on the photo mode usage after control is regained. I'm going to play around with it more tomorrow.

Link to original finding: Link to a recreation: