I think Ragina keeps those that remember FTL down in the insane asylum so they can’t inform the rest of StoryBrooke what they know.
I don’t think Ragina has a plan to send more people down there, at least not yet because not even Gold knows Belle is there.
I do hope that we get to see more of the insane asylum/ lower level of the hospital because we were left with questions such as; who else is down there? Who is the nurse? Who is the janitor? Do the people of StoryBrooke even know those citizens exist? And if Gold knows and sees so much how come he can’t see that Belle is alive?