couple ideas to consider:
a 7 conductor trailer wire is reasonably stiff, just run it through a couple loose fitting grommets and it would probably slide in the grommet rather than kink when the door opened/closed, some cable lube would help
jeeps with removable doors have the same problem we do. They added cable cover to the door stop strap and those are commonly available:
https://www.amazon.ca/Protecting-Adj.../dp/B07GZJNVVK