I think I must be doing something wrong with my kettle finings, either getting the dose wrong or (more likely) using out of date KoppaFloc. The below pics are of the aforementioned inaugural double batch. Not shown is the full kettle, post whirlpooling and chilling, which looked pretty clear (clouds of break were too submerged to see). I used 2 2400 W elements going full-pelt and chilled the 42 L of wort to 12C within an hour, so I am confident about both hot and cold break. Unfortunately I just can't get it to flocculate. Chucked a slurry of Polyclar PPVP into the whirlpool just for fun.
I threw the hop pellets in loose for this one, for no real reason but to see the effect of the whirlpool on them. As donburke suggested, I bypassed the chiller, but at the start of the whirlpool not the end, to encourage less hop material to go through it, adding it into the loop 10 mins after flameout. Its effect on flow is noticeable but not dramatic. After turning off the pump, the chilled wort was left to settle for about 25 mins.
After draining about half the wort:
View attachment 57963
As before, all the break is evenly dispersed throughout the wort. It does seem to sink as it wasn't visible in the full volume of wort, just doesn't actually clump and properly fall out.
After draining all of it:
View attachment 57964
Based on the hop cone, I'd say the whirlpool definitely works now. Maybe the angle of the nozzle is too acute, but I can fix that.
Pinning my hopes of BrewBrite for now, unless anyone has any other wisdom to contribute?