able sellers to give more detailed feedback on their buyers

Alfiesbricks

Personally I don't think it is fair that only a customer can give elaborate (neutral, postive, and maybe even negative) feedbacks on sellers but sellers are unable to feedback their customers. Unfortunately now and then you find yourself in a situation that your having a troubled experience with a buyer. Some of them are just rude. But now it appears that when beeing a seller, you have to swallow it and your not able to give a truthfull point of view on the experience. I like to point to the system in Bricklink, which personally I find more fair then the situation on BrickOwl.

Hoddie

The BL feedback system allows sellers to manipulate buyers into giving undeserved positive feedback. Not all sellers do this of course, but enough to make the entire system worthless imo. If a buyer is rude here on BO, block them, use the 'Report a Problem' feature if appropriate, and move on to the next.

White Horse Bricks

As @Hoddie has said, block and report if necessary.

To be honest even if you have given a buyer negative feedback, it wouldn't help me as a seller in the slightest. I'm not going to see the feedback before the buyer makes an order from me, and by then it would be too late to do anything about it.