Hoisting hardtop using roof rack mounts?

Hello folks. This is my first post. I just bought my first Bimmer-a 2002 M3 convertible.

The wife can't help me remove the hardtop so I am rigging a hoist in the garage. There are the four mounting points for attaching a roof rack. I want to use brackets bolted to these points to lift the top. I've actually made the metal brackets and they have holes for rope to go through. I will pull straight up by using bars that span the width of the mounting points.
Has anyone hoisted their removable hardtop this way? Has anyone mounted a roof rack instead and used to it for hoisting the top?

I guess I have a minor concern about tweaking these threaded mounting pads since the roof is aluminum. However, the roof is not that heavy and the mounts are designed to hold roof racks which could have loads/objects mounted on them that would be stressed from wind force, if nothing else.
Thanks
PS: bought the wife a 2010 525xi, with M sports package, too.