You can smoke a rump tail follow any tri-tip video for cooking times, I also use the tails in any beef recipe I do. I cut into small chunks when making beef stifado, also any beef & ale pies, beef & onion pies, it's very tender meat, when I brown it first I always use butter, but only cook for a few minutes or you will overcook and make it tough.
Any slow cook recipe for casseroles this meat is the best....I am going to make some pork & beef sausages and will use maybe 500gms off a tail in the recipe.
As you will see the tails are all meat no fat, so you have to be careful not to let it dry out while cooking..let us know how you get on..👍
Ice.