I fundamentally disagree with your first point. Actually, while travelling in and out you'll to give (or take) need LESS sheet. The sheet as a whole must be slightly longer to make the turn around the tramp ratchet but when moving the traveller car requires less additional sheet then without the tramprathet because the piece of sheet line between the tramp ratchet and the mainsheet block can largely arc from side to side and thus take up most of the traveled distance; this is of course for the same length.

If the tramp ratchet is say 1 mtr in front of the centre of the rearbeam then traveling the mainsheet 1 mtr down the rail (pretty much max on spi boats !) then the distance between the tramp ratchet and the mainsheet blocks goes from 1 mtr to 1.4 mtr.; a difference of only 0.4 mtr in addition to the 2 mtr give of the traveler line itself. This while traveling out with the current conventional system would require 1 mtr + 2 mtr = 3 mtr. So this tramp ratchet system needs 0.60 mtr or 20% less sheet when traveling out. This benefit increases when you place the tramp ratchet more forward on the trampoline.

I'm also not sure whether point 2 is much of concern after all the line wrap around the blocks with be close to 90 degrees and the ratchet block experience a load situation that strongly favours aligning itself properly.

But indeed some-one needs to try it to be sure. For now it is just a wild idea I had.

Wouter