Hi there, thanks for reaching out. This is a somewhat experimental role that I've been using in the US for awhile now. Happy to revert if the local community doesn't want this data.

The highest point of a feature is of interest to certain data consumers that may want to, say, label a peak at lower zoom levels even if it's not particularly tall. Adding nodes as relation members won't mess up other use cases since most data consumers ignore node members. This pattern is similar to the admin_centre role of admin boundaries and carries similar importance. The highest point cannot reliably be found through queries since sometime: 1. The point may lay exactly on the edge of the feature (such as Mt. Everest on the Nepal/China border) and may fail point-in-polygon tests (due to precision errors). 2. The highest point of a feature has not yet been mapped (common with smaller or flatter islands and boundaries). 3. Points with unexpected `ele` values may appear in the data at any time (perhaps due to typos or bad imports).