Aviation insurance policies are not "standardized". Each company develops and submits its own wording to each state. All policy forms must be approved by each state insurance department for states where the company plans to write insurance. State insurance departments are very consumer conscious and are very receptive if a company requests broader policy forms. Therefore, it is not difficult for a company to get state approval when they want to broaden or include additional coverage.
This is a companion discussion topic for the original entry at https://www.avweb.com/ownership/all-about-expansion-coverages