You assume the fish always swim AWAY with the bait slayer ..they may swim towards you or even along a little, then the sliding rig may help a little …..
It’s possible he had more hits “not hookups” because of it …just as likely tho – it was because a lot of the time he was using 2 rods instead of 1 lol ……elmo and I used 1 rod each …ginga had 2 but 1 with fish bait
I cant imagine ever bothering with that type of setup tho ……..but the one used at Kaikoura had merit ..
It used a running rig over a far greater distance , it worked similar to the casting latch on the sinker idea without any special sinker and also used a small float to lift the bait off the bottom away from crabs …
He puts a lot of time into rigging up …I’m interested to see what other ideas he comes out with.