Is there a way to selectively cache to deeper levels in certain areas? That'd be rad.
We're doing selective rendering with MapBox Light, which is deeper in cities. For this, it's better to have always-there zoom levels. Otherwise you grapple with the deep, deep problem of someone panning from a high-zoom area to a low one, or using an API like Leaflet programmed to zoom to a level. Unless you control the API and have a zoom-depth-api like Google, having a map with highly variable max zooms isn't an easy call.