The SEA 1180 ship has a requirement to support SOF delivery and amphibious ops. The Army will be acquiring a small fleet of Tactical Littoral Craft which could be as big as the CB90. The capability to support the TLC should be in the SEA 1180 ship. With the multi role mission deck and the requirement to operate MCM USVs in the MCM role it will probably be something well within the capability of the ship.Yeah, that would be one hell of an "atomic ant", but I cannot see why to put the CB90... that will only add weight without improving the capacities that a medium size helo and a pair of RHIBs actually give you...
BMT have a new multi role OPV design superseeding their Venator which has some intersting mission deck - stern dock - side davit arrangements. Still a large ~3,500 tonne ship for the RN requirement but some interesting deck arrangements to have this kind of flexibility in a monohull.
http://media.bmt.org/bmt_media/resources/33/RINA_2010_Securitor_Paper.pdf