That’s a taste matter. Being recalled that what is expressed is always depending on some technical details on every move, this is great when one is loving technical details and have all the leisure time to pay attention to them. This is going to be hell compared to sound defaults for someone willing to focus on delivering higher order feature/functionality which will most likely work just fine.

Unedefined behaviour means "we couldn’t settle on a best default trade-off with fine-tuning as a given option so we let everyone in the unknown".