I wonder why people don't fit a ratchet to the middle of the tramp and just lead the mainsheet from the normal blocks and cleat first to this ratchet and then to the crew or skipper. Meaning, not first along the boom and then down to the trampoline. Much less springiness of the trampoline in this new plane, easily made and out of the way when tacking c.q. jibing as the sheet layes close to the trampoline or even flat on it when you grab it between the blocks/cleat and this tramp fitted ratchet. You also double up on the ratchets on your mainsheet and increase holding power that way, especially attractive when using an autoratchet.

Additionally the upward pull on the traveler car is much less then when sheeting directly from the cleat. It should be enough to just stitch a small loop to the trampoline and tie an autorathet to that. Should work on a spi boat as well.

This has all they advantages of a centre sheeting system with hardly any of the drawbacks. The only drawback I can see is when you keep the mainsheet out of the cleat but pulled tight when tacking (note how this this never happens when gybing on a spi boat). You'll have to move your legs over the slightly raised mainsheet line between the ratchet and mainsheet blocks. This could even be an advantage as you can hold the sheet by pressing your knee onto it keeping your hands free to thumble the tiller across.

Somebody should try this one time !

Wouter