Quick answer
The core difference isn’t the paperwork, it’s the underwriting. Standard policies price a home using regional formulas and average construction costs. High-value policies are underwritten individually, based on the specific home’s actual replacement cost, its contents, and the household’s liability exposure.
In practice that shows up as: dwelling limits based on real rebuild cost rather than a formula, scheduled coverage for valuables instead of a flat sublimit, higher and more flexible liability limits, and access to carriers, like Cincinnati Insurance and Chubb, that write this kind of risk as their core business rather than as an exception to a standard book.