Like most labor saving devices, there is a trade-off between the fixed cost/effort of setting them up, and the labor they save. Most mainsail handling tools like lazy jacks are great for a single job (dowsing), and are just in the way the rest of the time. For example, I don't think your solid rod idea would work, personally, because of the pain of storing, then moving, a bunch of 8-foot tall bent rods in a hurry (where were you going to put them?). You can learn from history because sailing is so old that almost everything has been tried at some time in the past. I've never heard of a similar system working. Lazy jacks, and the related Dutchman-system that passes lines through the sail, have been around (and complained about) for centuries. I suggest getting on someone else's boat and seeing how they work their main. For example, I always laughed at lazy jacks, until I got on board with an older fellow on his 26 foot boat. He used the system so well, and had it tuned nicely, that the main literally tended itself. Turn to the wind, drop the halyard, and grab the sail cover. By the time you made it to the mast, the thing was almost perfectly flaked - 'twas magic!