Last update but I find it helpful to circle back around and close these loops when I can. I think we can safely say that the roo has been stressing the girls out. I put him in "chicken jail" (my coop that is so too small I only use it for isolation/chicken jail) for most of yesterday and a few hours this morning and Link laid an egg! A normal egg! I'm going to have to experiment with how long Mr. Roo is in chicken jail, because I do want him to be able to roam a bit.
I did also switch their food out to pellets, because I keep anxiety-reading new threads here and it seems like crumbles are less ideal, since they can pick out the bits they like. But I did have a day (4/26) when NOBODY laid and then yesterday 3 out of 4 were back to normal with him in chicken jail. So I'm pretty sure the change in food didn't do it.
I have a posting on Craigslist, NextDoor, and reached out to a local farm animal rescue. Unfortunately they are full up on roosters. Next week I see my doc and she also has chickens. Maybe she'll know a guy. Like, yeah he's annoying and I'm probably breaking some ordinance or the other, but he's also beautiful, healthy, and nice. This is why I tried to get all pullets, sigh. So I wouldn't have to face this.
But Link is better! So that's a win in my book