Set-coords arc floating precision

Hello, My name is Nate. I have never participated in one of these lists before so I don't know the protocol so I apologize if this isn't the appropriate channel. I am working on an application where I need arrows on the end of arcs, which I am accomplishing by adding very small lines to the end points. However I think I have discovered that set-coords when used with an arc won't update the position unless the coordinates are integers which makes my approach impossible. Is there a workaround for this issue? Thank you, Nate