Thanks, I'll send you a pm when I have a date in mind, thinking about the end of this month.
I doubt there will be red bugs in your refugium, but is it worth the risk to you to possibly have to repeat the treatment? I'd still suggest you move some LR from the sump into the "rescue tank," as this would repopulate your system's pods relatively quickly when the rock is returned. You could also get some 'pods in a bottle' if you're concerned about not having enough to support your reef. Just my opinion (he says, humbly).
I think it's worth it to try and salvage as many crabs/shrimp as you can. It seems like the bigger the tank, the more people are willling to just nuke the whole thing and not go to the effort of saving them, but since you already have a functional place to put them, it would seem silly not to try and rescue them. Maybe you could even rig your fish trap with food, soon after a feeding, so that some of the shrimp would wander in there, otherwise they will probably be very hard to catch. Even though my peppermint shrimp climb onto my hand whenever I put it in the tank, I wasn't able to manually remove them, and a net didn't seem to generate the same response.