RMR on an FNS a no go?

After sending my FNS-9L out in January to Continuous Precision through my LGS I found out last week that they cannot get the RMR to work on it's slide. From the conversation it's my understanding that there is just not enough meat on the slide top to properly mount it with out a substantial plate. Does anyone have an RMR mounted on an FNS pistol and who did the work? I'm debating trying to contact ATEi to see if they can do it, or just putting the RMR on my 1911 instead.