Whether it's Kessil or Radion, you'll need multiple fixtures in order to light sps effectively. There's plenty of par and spectrum to grow and color sps with Kessil's. I have two AP700's and a single 360x over my custom 90g. I'm going to replace the 700's with 360x's in order to place them exactly where I want them. I do use Orphek OR2 blue plus bars on three sides of my tank to add a little pop, but I can easily use all kessil's and be covered. I'm successfully growing and coloring sps and clams in my tank just fine. The clams, two maximas and one noae are on the sand bed and are growing. I honestly think 95% of sps guys just use radions, mh or T5 because there's been success using those fixtures, but that's not to say those of us who use Kessil can't do the same.
I grew plenty of sps in my 22g nano with three 160's. I used some T5's in the end because I got a great deal on a T5 fixture and I knew I was going to upgrade to a bigger tank and didn't want to buy anther 160, especially when the T5 was cheaper than the 160.
Top down before the upgrade. You can see the three 160's.
Just a couple from my 90g.