Sounds awesome. Mine will be plumbed similar, except there are only 2 drains on it, so one will be the primary with a gate valve, and the other will be the secondary/emergency, with maybe a trickle running through it.Looking good. Cant wait to see it with water in it.
I used the modular marine overflow its essentially the same thing. I plumbed mine as a full syphon and 2 emergency standpipes. With a little adjustment of the gate valve its dead silent.