I recommend not plumbing the frag system into your display system because if you have a crash or other issues (nudibranches, AEFW, etc) everything gets infected. Keep things separate so you always have a "safe space"
I would also recommend a stand alone QT if you have the room to build one and put anything new into that tank until you are positive all is clean & healthy, no exceptions. You may want to consider keeping a bunch of peppermint shrimp in the QT as well and they will clean any new sps of AEFW.