interesting! those holes on the bottom would have to be on somekind of CLS. if they were supplied from a sump, then if the power goes out, you are in big trouble.

you can get check valves, but they are unreliable and are subject to clogging. either way not something i would risk.
those are small holes, looking at my chart those holes will only accept bulkheads for 1/2" pipe.

hard to get enough flow using that.
those holes in the middle would be great for blowing out underneath the LR.
let me think on this some more.
G~