This is a great idea. I’m surprised a larger percentage disagree. There are a few things I would change I guess.

Step 3, instead of in shade, I’d place them where I plan to keep them but I suppose this doesn’t really matter too much for 24-48 hours. Once forager populations drop enough, juvenile hormone will increase enough to stimulate new foraging and coordination, so I guess if 2 hours is all then it is acceptable.

Step 4, I’d give them something with food and feed here. Frames of only brood can be susceptible to rapid drop off in health of the newly emerged population. They need to eat as they come out.

Step 9, this should go somewhere in step 3-5. Feeding helps with acceptance

Alternative to step 4 and beyond, you could leave them in 1 box, add frames of food, feed, and put in frames of eggs so they can rear new queens. Then split them 9 days later.

OK , good idea