Would you mind filling me in on some of the ways it could go wrong?
This is a code 0, about 100% jib equivalent, very flat cut (intended for reaching) with a sewn in HM luff line that it is furled onto with a continuous line furler. The yankee sheets will be tied out of the way when this is flying and this sail will be bagged on deck when the yankee is flying. The tack will be aft of the jibstay (ahead of the forestay w/staysail) and it will be hoisted with a spare jib halyard where the upper swivel will likely be 2 feet below the jib furler swivel. As you suggest, there isn't much room in front of the cranse iron and the furler would foul with the jib furler.
I bought the sail used from a gentleman who was using it in a similar way on an Ingrid 38, and here is a
sister ship to mine doing something similar.