I have an Innovative Marine 30L tank (36" long 30g) and Prime lights, and I've done a TON of PAR testing with different configurations on my tank. Here's what I've found...
With two lights, space them in 10" (on center) from each end, and mount them 10" above the waterline. That will give you the best, most even coverage with two lights.
What I found that was kind of my "ultimate" setup (and the way I currently have my tank lit) was to have three lights. The outside lights are spaced 8" on center in from each end, and the middle light is centered. They are all still 10" above the water line. Running 3DReefing diffusers helps even out the spread a bit, too. I run them on all my Primes, on all my tanks.
What I did with the three light setup to really dial it in is to run the end lights as a pair (in the app), but run the middle separately. They all run the same color mix and the same schedule, but at different intensities. Because of light overlap, the center light runs at a lot less intensity, and my PAR is SUPER even from end-to-end. I have all LPS and softies, so I don't need crazy PAR but, for example, if my outside lights are running my schedule at 65% of peak, then the middle light is running the same schedule at about 35% of peak.
I hope that makes sense.
As for the schedule itself, pretty much any of the "big name" ones (Pirates of the Caribbean, Saxby, etc) will grow coral as long as the intensity is set for what you're growing. I like simple, so I basically run the BRS AB+ setting. I use a 60 minute ramp up, 10 hours stable at the peak, then a 60 minute ramp down. I tweak it a bit by ramping the whites up later and down earlier so that I have a nice blue viewing window in the morning and evening, but that's all personal preference.
The most important thing is... You HAVE to test YOUR tank with YOUR lights and YOUR schedule with a PAR meter. Using someone else's settings might get you close, but only a PAR meter will get you where you need to be.
