I don't know why you would want to put a poop board over the nest box bottom after removing the dividers, it is already a board, no???
Poop boards and scooping PDZ is fine, if you want to scoop poop every day. I have deep bedding (pine shavings) and just run a rake through it under the roost areas every morning. Takes 2 minutes and no "bucket o' poo" to get rid of. Of course it depends on the size of your coop. Since yours is big enough to walk into, I think the same would work for you.
The cat box in the house for the 3 indoor cats, that I HAVE to scoop
Just now TJ??? If you were not directed to the Mama Heating Pad brooder thread after your coop fire, I apologize. I tell everyone about it. NO chance of a coop/brooder fire, WAY more natural method of the chicks getting heat when they need it instead of living in an overheated space, natural day night cycles, impossible when using heat lamps.
https://www.backyardchickens.com/t/956958/mama-heating-pad-in-the-brooder-picture-heavy-update