From what I have heard from people in the business. If they have shares on hand and they can make money lending those shares they will lend those shares.

These brokers make no money on the trades. They make their money using your shares. That's why there are so many brokers offering free trades.

Bottom line, it there is something that would block their ability to make money from your shares they would not offer it to you in the first place.

An example in your case would be they would not allow you to put a sell order a certain % above current price. That would block you from doing what you did. The fact that they allow you to put that order in tells me it means nothing to them.

From what I have heard from people in the business. If they have shares on hand and they can make money lending those shares they will lend those shares.

These brokers make no money on the trades. They make their money using your shares. That's why there are so many brokers offering free trades.