GeoChart projection support

[David Warner]

Hello,

I found a post from 2013 that mentions a projection option for the GeoChart visualisation and lists 'mercator', 'albers', 'lambert' and 'kavrayskiy-vii' as the possible values (with Albers and Lambert supporting options for parallels and origin).

This option still appears to work fine, but I'm a little hesitant to use what seems to be an undocumented API. Is the projection option likely to be officially supported at any point (and conversely, is there a chance it will be removed entirely)?