Has anyone leased a broodmare and what was the agreement like? Pay all up front? When she checks in foal? What is she aborts? Good bad and ugly please

I am currently leasing out my mare who got hurt and couldn't run any more. I found a good place for her and I am not charging anything. They keep her on their property, pay all expenses, and she is given back to me in the same condition she left and in foal to their stud. We signed a contract that I found online. I modified it slightly. They also paid the $100 breeding lease through AQHA.

have leased several, feed lease, mare stays with them until foal is weaned. Insurance on the mare and all vet bills are covered by them. Has always worked out great.