Flood Prevention...Am I on the right track???

Thinking ahead on my upcoming build that will include a hob overflow (fully understand the benefits of drilled but it's not going to be an option). I've been reading everything I can find. I think I understand the siphon issues that could cause a sump flood as well as the measures to take for reducing that risk as much as possible. My question is around flooding of the display tank due to lost siphon. If my calculations are correct, I could hold my display water level at the bottom of the top trim and have the ability to hold approx. 3.3g more without flooding. If I design the return area of my sump to hold no more than that or position the return pump so that it would run dry at that level....would I be safe? Is that an appropriate volume of water for a return? Thanks