It is sneaky. I got them used to it, then I'd carpet the water with 2.2mm pellets directly above the trap. All the CNBG look up while they're eating, so they're easy targets.
What is your preferred transfer method for that number of BG now?
Hand pick out the HSB, then put the BG in some water tank, and then transport to their final destination? What type/size of tank are you using for your short transfers?
150 qt Igloo with a 4" vent on the top, sea salt and clove oil, a flat bottom Cumings net(well worth a little extra), A Boca for weighing the fish in the net, a 34" ruler that fits in the cooler, a clean 5 gallon bucket, and a small O2 bottle with a priceless to me, Premier Industries pre-regulated O2 valve. Not having to tote a 2 dial regulator and flow meter is worth a couple of hundred bucks. All that junk fits in the cooler, and the cooler fits the Mule, so it's easy to tote around. For short haul time wise, I've moved right at 20# of LMB with no issues. It still makes me nervous, but moving the same volume of CNBG, not so much.
Yes, the HSB will all go back until they hit 10", and any red tailed CNBG also goes back. They're getting to not become a LMB slurpy because of that tail color.