I smoked mine but you dont need to trim it for that. The fat protects the meat. I smoked some shoulder for good measure as well.
I made the mistake of buying a lamb breast. Looked like spare ribs of the lamb. Came across it at wally world like
Damn, I trimmed the hell out of it and threw it in the oven. That shyt wasn't even edible all that damn grease. Threw it out.
I will buy chops (them little lamb tbones the shyt) and ground lamb but never the breast again.