Person is right, cool name by the way.
Photoreading 3 books a day is one thing, but Preparing, Photoreading then postviewing is entirely different. What exactly do you mean by "PHOTOREADING" something, running thru all the steps or just the one? Thoroughly Photoreading (all steps) 1 book every day to me is better than blasting thru 3 - unless you really have to do it for REAL, for school or work or something. If you are practicing then doing all the steps works better.
A 300 page book is just like any other book. If it has chapters, activate the ones you're most interested in first, then hit the other ones last, if at all. I'd do the same with a 800 page book. If it doesn't have chapters then just go by time, after 30 min, take a break then start again.
If you are going to PR multiple books a day I'd at least make them related OR separated by a "prepare" step. Photoreading doesn't strengthen the bridge, Triggers, questions and MM does more than anything else so if strengthening the bridge is your goal then you can't avoid doing any steps and basically have to run thru them all on a book.
Photoreading books without activating them works best if you have some reason for doing it. Just doing it is a great exercise but spontaneous activations are few and far between in the beginning and increase over time IF you keep going.
You can't have someone tell you how to have spontaneous activations. If you've ever had an idea come to you out of thin air, seemingly right when you needed it you know that you can't force it. All you can do read more and more.
But photoreading alone will stimulate intuitive part of the brain. And intuition is the key for spontaneous activation. Any thought?