How should I tie a bike to a hitch mounted bike rack to keep it from swaying into the bumper of my vehicle?

I have a couple bike(shaped object)s I’d like to transport to the local state park for fun in the sun in a few weeks. I’m looking at a number of hitch mounted bike racks for my vehicle. It’s pretty obvious how to use the rack (general example pictured below), however I can see the bike swaying along the front-to-back of the vehicle axis, potentially rubbing the wheels or handlebar against my vehicle. I’ve considered a handful of solutions, but was wondering what (if any) other options there are.

1.) Tie the bike to the vertical rack tube wherever it fits, this way the bike is held firm, but it is not straight up and down. This puts the wheel very close to the bumper, so there is less tolerance for any sway before tire-to-paint contact occurs.

2.) Weld an additional support perpendicular to the vertical tube halfway up which I can tie to the bikes to using the downtubes. This way the bikes remain more or less vertical. The downside is that I have to weld something, and I’m lazy.

Are there other solutions to this problem? I understand the bikes are quite heavy and tied on the top tube so the center of gravity helps reduce sway, but I also understand I’m very fond of my vehicles paint job and would hate to have a bike tire rubbing on it for 200 miles without me noticing.