Would this make my top bow?
 

I am making a top hoist based on some versions of a Jeep top hoist. Many of those use straps that run the length of the top along the inside corners. They enter at the window opening and exit out of the hatch opening. One strap on each side. Those straps are hooked to rope rigged to a system anchored to the ceiling.

Could this cause the Blazer top to bow over an extended period of time since it is not supported in the middle or the bottom?

Any thing else that I should keep in mind?