For a toothless big wide, (for your machine) I doubt you'll be prying on ledge. I'd use mild hot rolled 3/4" x 4" for the cutting edge. Edge it with a piece of high manganese grouser stock. With the bucket sitting flat right side up lay the grouser stock on the floor flat also. This gives a flat plane edge to "Rub your bevel" like a woodworker seeks to do.
For me digging a ditch or hole is quick. Properly refilling it, leveling it, raking it, and picking the rocks takes time. I often dig ditches. I have a number of trays made from 275 gallon oil tanks cut in half. A short chain is welded to each corner. Using an extend a hoe, I can put spoils in them, dig 10 feet at a time, install conduit, and sand, and picking up each tray, set it on the edge of the ditch. Unhooking two chains, I tip it into the ditch.
This keeps the mess as wide as the ditch. No scraping the grass to clean off the spoils. I can smooth out the ground ready for a hand rake before moving the tractor. The less driving the tractor around, the less damage to a lawn.
I can adjust the tractor stabilizers to place the cutting edge of the bucket on the ground level, but reaching over a spoils pile to refill a hole is better accomplished with a wrist, and a longer reach excavator. Us guys with smaller reach need a different way.
Willie