I found this model for a fishing rod holder, but couldn't really see how to mount it. It either had no mounting mechanism or required a screw on each, which is absurd. I added a plate that the hooks mount to with two screw holes that means it only makes two holes. Any screw should work as long as it's in a stud or has a drywall anchor, but bigger is better if you have it.

It holds the rod by the bump that comes before the guide, which means the guide is suspended in the air and never touches the rack. As such, it has no force on it and you can safely store your rods like this long term without risk of damage.

It's not modular, but you can print up to 9 at once on an A1 mini, which means that in one print you can have mounts for up to 36 rods. You should print in PETG, and though I don't think it's an issue, if you're worried about scratching rod blanks just put some felt or vinyl on the point of contact. It's perfectly strong when printed standing up, but if you're really concerned about it or hanging absurdly heavy rods you can print it flat with supports.