Typically, Berly will end up ruining a good kingy spot. Yes it will work some days, however i find that people find kingy haunts, and berly the crap out of it. Pretty soon you will have the yakka's bream, trevally, sweep you name it, take up residence, every sort of fish that puts a very quick end to your live squid or cuttle.
So for me, no berly, and patience in a known haunt.
I was lucky enough to actually be paid by fisheries to assist them in a tagging kings of all sizes.
We had 17 under water recievers placed in various places around the harbour, these recievers picked up the fish as they passed. Most fish passed all 17 recievers in one day, so yes, they continually move.
To answer your question as to why they didnt bother the Yakkers at all ??
This is a bit of a stab in the dark but I have found Kings to be a very focused feeder. they are either onto yakkers or squid, or cuttle or garfish etc. They will bite on one, and not the other. I have noticed that particularly late in the season like now, that Pillies do do the damage. This is perhaps why they didnt bother the yakka. PErhaps they knew they were safe ??
Baldy