Some questions re: single line reefing.
First: Do I really want to do this? I've long been used to lowering the halyard, reefing the tack, tensioning the halyard, then tensioning the clew. Single line seems to tension both together - to the same tension. Problems?
Second: Some systems use a single line for tack and clew, while others use a moving double block inside the boom. Does the moving block do anything? Provides no advantage that I can see. The moving block system just seems to require a lot more sheaves at the fwd end - some of which may or may not be built into the casting at the fwd end of the boom.
I currently put in both reefs by going to the mast. Hooks at the tack and then cammed lines out the bottom of the gooseneck for the clew. Double line to the cockpit means running the halyard and 4 reef lines (and the winch) aft. Single line to the cockpit means running the halyard and 3 lines aft, but more blocks at the gooseneck.
Biggest difference that I see is that the second line for the clew would have to be rigged all the time (at least through the tack and the boom). Currently, I don't rig the second clew line until after putting in the first reef.