Hi, I'm late to this party and have not read the whole thread obviously (I will, though!). But here's my thinking so far. Ben, you are thinking of having a slide-out tray. Would that be the only floor in your coop? When would you pull it out? I mean, when could you be certain none of the hens would be in thd coop so you could pull it out, leaving a big gaping hole, dropping the hens into the run, or would that be okay? Or would you have a hardware cloth floor above the tray so you could pull it out even if the coop were occupied? The drawback to that option is that "hwc" is hard on their feet, so no, that might not work. Hmmm. But if you just have the tray, you need a big enough gap so when you pull it out the poop doesn't gum up at the opening. Should be at least a one-inch gap, I'm thinking. For four hens you'll need a tray 4' x 4', that's going to be a bit awkward to take out and clean off every day or so. Will it be bare besides the poop, or will it have bedding on it too, like wood chips or shavings? Could get very messy, walking that over to the trash bin or dumpster. Especially in a high wind or rain. And you have to maneuver this poop-laden tray out the run door to the dumpster without letting the hens loose. Mm-hmm. Yeah, I'm seeing some difficulties here.I don't understand why I'd be crawling around in chicken poo and dust, if I have a slide out tray, or if I have a big access door where I could rake out the "stuff" into a bin. I must be missing something.