Specifically if they butcher beef. Do they further trim what are scraps from butchered animals that wouldn't be worth spending the time to trim for commercial sales?

Depends. They like to be called meat cutters these days. A friend of mine gets the best cuts for himself. The average Joe has no clue when it comes to cutting meat.

The butchers I worked with ate mostly ribeyes.

Typically the scraps of what they broke down ended up as ground beef.

I follow a YouTube channel called Just a Few Acres. He pasture raises chickens (butchers himself), pasture raises turkeys (butchers himself), pasture raises cattle (uses a pro butcher), and pasture raises pork (uses a pro for feeder pigs and self-butchers non-productive sows that are too big for pro butcher's facilities). He sells the chicken, turkey, beef, and pro butchered pork at the farmer's market. Most episodes, he ends with showing what he is grilling for dinner:

Chicken - typically cooks whole chickens

Pork - a little bit of everything as not a big price differential between cuts. Pretty often it's delicious cuts that don't sell well such as pork steaks which he says he prefers to beef ribeye steaks.

Beef - big price differential between cuts so mainly the less expensive cuts such hamburger, not as pretty of steaks as customer steaks, etc.