a) Getting it to work Just Right really isn't that hard. Use "quick knots" and the join between the ropes will sit in just the right place, every time you rig. Tie a figure of eight at the same point in both tails, push a loop of rope through each eyelet, and put the figure of eight through that loop. From a rigging point of view it's easier than tieing a figure of eight in the end of a rope tied through a centred eyelet, because it's easier to undo.
b) The traveller is very sensitive. Dropping the traveller just a couple of inches when it's really honking makes a big difference, so keeping it properly centered when it's not seems sensible.
Attached is my current effort. It feels pretty solid, but we'll see how it holds up.
