Mechanical difference between roller furling and reefing?
You should be able to reef with any furling system that has the extrusions covering the headstay. Without the foam luff you may not get a real good shape but that has never been a real issue with me. I''m usually just trying to reduce sail in a hurry.
Some furling systems incorporate a tack swivel which allows the belly of the sail to start rolling up before the foot and that is also said to give a better shape.
But as was mentioned earlier, if your system is consists of only the furling drum at the bottom, a swivel at the top and the sail has a wire luff, then it was made for furling only.