Here’s what seems to be an important factor in choice of homemade hangers but unfortunately will not be evident at the initial time of choosing.
The margin of user error allowed during its construction and/or its use.
A hanger with too little margin for error will have a higher percentage of users experiencing problems. The design as intended by the inventor may be perfect but it has to be duplicated by others ( who are only human ) who have penises in all shapes and sizes thereby requiring possibly a high degree of customizing the hanger, further reducing the margin for error.
Throw in the various wrapping nuances that each one of us has and you can now see how safety thresholds can be breached.