I ride Bosco's on my Appaloosa (and have had them on many other bikes over the years). "Should" is all in the eye of the rider. I find if it's comfortable on shorter rides, then it's good for about anything. On longer rides, I tend to get more flexible as the ride goes on and bend over more. My hand position doesn't change, but lower back, shoulders and elbows move around to accommodate.
Your numbers seem reasonable. If it feels cramped or too upright, you can always try a longer stem, but as long as you're comfortable, that's the main point. Folks ride their Bosco bars at a lot of varying heights and reaches, so I imagine a lot of varying elbow bends as well.
Best,
Eric