Depending on your layout what equipment where the second bubble trap might be a moo point. My design was similar to yours but instead of a second bubble trap I just did a baffle but I routed out a 4inL x .75 in h hole in the baffle just incase something were to happen to cause the water level to drop in the sump it could buy me a little extra time till the pump went dry. That's just how I did it but am nowhere near an expert.