You're right on target with your assumption on production. I generally get 1 pod per plant, sometimes 2, but usually just 1 worth picking. It pretty much depends on what I'm going to do with the okra as to how long I let it stay on the plant. If pickling, I tend to take them in the 3-4 in range and only use quart jars when doing so as I find pint jars just aren't big enough for the job.
If grilling, I like the pods just a shade bigger than 4 inches, especially if making "rafts" to grill them. By that I mean placing about 6-8 pods by laying them on a cutting board one behind the other with the pointy ends opposite of the one in front of it, then skewering the pods through both ends 90 degrees opposite the pods. Just a bit of olive oil, sea salt, black pepper and garlic powder and they are good to go on the grill.
If smothering them down, (stewing), I'll let them get a bit longer but not woody. They are cut in 1/2 inch discs across the pod and put in a pot with a bit of oil (bacon grease for this guy), a large onion, bell pepper, a few stalks of celery, garlic, petite diced tomatoes, Worcestershire sauce, a few dashes of hot sauce, a couple Bay leaves, salt, pepper and about 2 cups of water. All vegetables finely chopped by the way. I'll let this cook down for about 3 hours on a low boil and it will break down nicely. At first it is slimy as an eel as it first heats up but that goes away in a couple hours time. This is what I use as a thickener in gumbos and soups. I have a gas stove and use a heavy heat diffuser under my cooking pot to more evenly distribute the heat, but still stir it pretty often to make sure it's not sticking.