Interior and Upholstery 3 point harness mounting

I have Corbeau seats and now looking to replace the factory style belts with a 3 point Corbeau harness. The geometry of the factory vert belts just isn't working well with these seats and looks out of place especially with the harness slots in the seats. I am also working on a custom rear seat delete/quarter panels and the belt mountings are tricky to work around. Has anyone used these in a convertible? Would it work to run the shoulder harness strap back and down to the rear seat belt mounting bolt or is that too low? Does it matter much how low it is mounted in the back if it's coming over through a harness slot? https://corbeau.com/3-point-harness-belt/

Well, I'm talking about the rear seat belt bolt holes behind the rear seat back, not the floor. I know you shouldn't angle more than 12 degrees down from the harness slots but these holes seem back far enough to avoid issues. The pictures of this 3 point harness on LMR show the rear strap going back to the rear seat mounts in a coupe, I'm wondering specifically if anyone has used these in a vert without a bar. If I have to do a bar I'm not using them but they seem like they would work.