I have 20+ rock flowers in medium flow and directly under a ai vega, tank is only 10" deep light is 4" above I've also seen them directly under halide in frag tank with no problems. All mine love light plus flow and lots of food.
Current pic of rock flower tank
Currently I have had 2 females release 10+ babies each in the last 6 months or so. When I get new ones I put in a low flow area with small rocks to attach to rock then move where I want it for the most part it works but some do move. Rock flowers and euphyllia don't get along, rock flowers die. most other thing are fine and are fine right up next to each other. I think there great for a mixed reef