But we should all realize that the leverage is NOT reduced to zero. Unlike the free-sliding jet diver example you cited, that spoon is still attached to the beadchain. And with only one anchor point for the spoon, it's still free to flap around pretty wildly as a fish shakes its head during the battle.
Yes, I believe that I did mention that the spoon is not totally out play after the hookup.
While the Jet Diver can slide up the line, the connection to the fish no longer goes through the diver and it doesn't tread water as positively during the fight.
So there are two features that the leashed Jet Diver has in common with the Bead Chain Spoon.
With the BCS, the connection to the fish no longer has to flow through the spoon which seems to make it more difficult for the hook to be thrown. Being tethered on one end, it goes neutral as the fish races around instead of gaining purchase and possibly interfering with the hookup.
Have you ever considered attaching the beadchain to the butt of the spoon? Yes, I realize it would look really goofy. But consider this....
You still retain the isolation of the hook from the spoon, but now the spoon is anchored under tension at 2 points and less able to chaotically flap around during the fight.
Yes, I mentioned a lightwire "hairpin" previously that would connect at the rear hole and release with torque.
At the time I thought that fouling might be a problem with the bead chain during the cast.
To have a "hard" connection to the tail of the spoon would still require that the connection go through the spoon.
The long "tail" would probably have a negative effect on spoon action and the spoon would be able to tread water during the fight (ie. flashers and dodgers).