I would just call it a full hollow. Singing hollow, extra hollow, etc. are all just different versions of full hollow to me.

There does not seem to be a definitive way to judge the hollowness of a razor. I remember asking about it awhile back, and the identifications do not match the depth of the hollow in relation to the spine and edge. Taking measurements off of various blades, most full hollows start roughly halfway up the blade. Some more, some a bit less... Assigning a degree of hollow to a blade is subjective. There is no way to measure a blade and say for certain "how hollow" it is.