Only lease them the depths they are targeting. That way if another company identifies a different depth zone at some point in the future you can then lease that zone and get paid again. It’s possible to have multiple depths(zones) being operated by different Operators. In my opinion it’s more valuable to have a cost free royalty clause in the lease instead of a couple hundred bucks more per acre for the lease bonus. Cost free means you get your portion at the well. You do not get deducted for. Treating, transporting or storage and other associated fees