,
If your putting a weir on both sides, then you would have to have one lip lower than the other, to achieve a skim to the right side only.(That weir by your design will be a dry dock with locline poking over the top correct.?)
Same goes for your durso reserve, It has to be low enough to be within the confines of the tank obviously, yet your main dump pipe will have to be lower than the durso neck.
Which means
A) your doing a modified bean animal approach,
B) due to the size of the durso coming in, the water level will lower in the weir unless you throttle the durso as well and
C) you will have a straight dump pipe in the base, and extra reserve plumbing on the backside of the DT.
Is this a correct observation?
Im thinking of throwing out the suggestion of boxing it up as your going to, yet look to drill an extra hole in each side.
One will be the dump on each side, the other a sealed return, all within the weirs. Obviously this changes deployments, however I'm not seeing your entire scope yet, so its a little hard to add suggestive inputs so far, namely that will hinder or advance your current plans :)
Tagging along anyways bud. Look forward to seeing how you go.