Custom grid lines

I’m trying to create a custom grid (grid lines). I’ve seen the Cartopy graticules example in the Geoviews Geometries documentation:

graticules = cf.NaturalEarthFeature(

But can’t find any other documentation on how to go about creating custom grids. I’d like to create a grid that matches a web mercator web map tile grid at a specific zoom level.

That feeds into a more general issue in that ideally we’d provide Feature elements which dynamically increase the scale and clip to the current extent. Could you file a feature request on GeoViews?