Question from an amateur working on a big project with big breadboards. Dining table is 72”x38” including 8” breadboards, made from 8/4 walnut. Needless to say, the 3+ feet of walnut at the ends are HEAVY. I was planning to attach the end with 4 haunched tenons. Problem is, the tabletop boards are a little short, and I think I only have 2” max for the tenon lengths. The ~6” of unsupported 8/4 walnut makes me a little nervous, especially considering full plates of food and people leaning on them…Any suggestions for a safe minimum tenon length (and mortise depth, for that matter)?