Sorry to log in on this topic so late but since most of the responses you received were from Supers and your Maramu has been re-rigged so as to not be easily adapted to the Amel downwind layout, I thought perhaps I could offer an alternative.
As brilliant at the double headsail setup on the SM is, it may not be the best approach. There have been studies to indicate that having two headsails meet at the forestay with no gap is not optimal. Having a gap between two headsails provides an escape for the build up of pressure which is advantageous for gusting conditions and provides some relief for the standing rigging without significant loss of drive.
On Libertad, we have a second headsail with an integral stay that is raised on one of our spinnaker halyards and poled out opposite to the poled out genoa. The sail is cut so it doesn't need to be furled and the integral stay is relatively light ss wire because we don't fly it in any wind greater than 15 kts apparent. This configuration closely mirrors the SM rig and provides a gap between the two headsails. I suggest you don't overhaul your forestay/furling system when the same/similar result can be achieved with a custom headsail.