No it does not bother the SPS. But if it comes across a damaged LPS like acan it will pick at it and eat the damaged tissue. It does not go after the healthy tissue. My strategy with adding any LPS is to first get them all healed up and healthy before adding them to the tank.
Beautiful Marginalis.. The second one I've seen.. I photographed on a while beack in my other thread.. How is it eating is it a good eater or is it a hard to get eating fish like it's cousin???