I have the Garhauer version and have found a new use for them which is a simple variation of Captain Kimo's Poor Man's Traveller for the 26X shown here...
http://www.macgregor26x.com/modt/index.php?view=656
Use 25 ft of 3/8ths line and hitch a carabiner (snap shackle) to the center point of the line. Snap the carabiner onto the boom bail. Run the respective ends of the line through the EZ Cleats.
This now gives you better control of the X's sail shape.
When close hauled, with the boom close to center, cleat off the windward end of the line, release the mainsheet and leeward end of the line. All the tension will now be in the windward line which will control the boom's angle without pulling it down too much. This will restore draft to the sail that the mainsheet would have over-flattened when sheeted so far in. It will also allow you to get the boom to center, or even over center, while still reataining draft in the mainsail....... i.e. what an ordinary traveller does. If necessary you can tension the leeward part of the line to flatten the sail.
In stronger winds, you can let out the windward line and tighten the leeward line to flatten the sail and reduce heel......... effectively an more instantly available boom vang, or the same as letting a traveller out and tightening the mainsheet. The boom vang can stay released until you need it for downwind.
It sounds complicated to operate but once you play with it a bit it makes sense. When tacking, I retighten the mainsheet and release both EZ cleats, tack, then readjust the EZ cleats and release the mainsheet when stabilized on the new tack. When going onto a run, I again take the tension on the mainsheet, then unclip the carabiner from the boom and let the mainsheet out.
It's a simple mod that (unlike Captain Kimo's mod) lacks any mechanical advantage so in strong winds you need to use the mainsheet to overcome the high forces and position the boom close to where you need it, then make small adjustments on the EZ cleats and then release the mainsheet.
It may sound like too much trouble but I have been amazed at how much difference subtle changes in sail shape make to sailing this boat, and has made me realize how hindered we X drivers are by the lack of a real traveller. It's far from being a perfect substitute for a real traveller but is a vast improvement over having just a mainsheet. Before, I had great difficulty in making all the sail's telltales fly simultaneously, and in stronger winds had problems trying to reduce heel and yet retain some power in the sail. It also helps me make small adjustments to balance the helm and reduce the tendency to stall the rudders and round up.
When I first considered the idea, I just bought some cheap line and a spring clip from Home Depot all for less than $20, found out that it worked, then upgraded the hardware to stronger marine quality.