Sail catcher
I keep harping on about this, but with a sail catcher you don't need the lazy jack arrangement. It occurs to me that on Jami's sail catcher, that lazy jack arrangement with two attachment points on the aft part of the sail catcher may be intended as a way of spreading the load more evenly on the tubular frame of the sail catcher.
Well, you don't need to do that, and the downside is, it presses on the leeward side of the aft part of the sail and interferes with its shape, more so than a simple pair of aft lifts. At least with the Amiina sail plan, the aft lifts should be attached to the sail catcher as far aft as possible (just forward enough so the yard can not escape when hoisting the sail).
And I believe it is better if the lifts are not attached directly to the aluminium tube frame.
I collided with a channel marker the other day and broke one of the tubes on the sail catcher, at the mast, and it seemed at first like a disaster because of course the sail catcher is a necessary support for the bundle, when reefing. The result of the accident was that I made a discovery: attaching the lifts to the tubular frame, as Jami has done and as I had done, is a mistake.
Better to attach the lifts to a reinforced attachment point on the sail catcher itself. Those aluminium tubes can then be lighter, as they then carry very little load, and only serve the purpose of stiffening the edge of the sail catcher. So those tubes can be made from lighter, cheaper stuff - and one attachment point for each lift is sufficient as the cloth sail catcher is carrying the load of whatever is in the catcher, instead of the tubular frames.
My breakage also showed up another advantage - if the lifts are not directly attached to the tubular frame, this allows the starboard tube to be easily slid back in its pocket, to allow the bundle with its catcher to be easily released from the mast, a necessity for trailer boats. Previously I had the starboard tube in two parts, with a join at the mast for easy release. This is where it broke, and why it broke. By transferring the forward ("mast") lifts to the catcher itself rather than the tubes I was able to remove the broken parts easily - and later, to slide a singe full-length replacement tube easily into the pocket. Its an improvement now, every time the rig has to be dismantled.
One last further tilt towards KISS: the U-shaped tube joining the tubes at the front of Amiina's sail catcher frame appears to be un-necessary. I made one for the front and one for the back out of plastic. The back one interfered with the sheeting and I simply took it off. The front one broke and I never replaced it.
Two simple parallel tubes appear to be all that is necessary as a frame for the sail catcher.
And two simple lift pairs, one pair at the mast and one as far aft as possible, attached to the catcher and not putting load on the aluminium tubes, interferes least with the sail and appears to be all that is necessary to guide the spars into the catcher and muzzle the sail when reefing or handing.