Set map zoom in shortcode

I have individual pages/posts showing a close-zoomed map (my default zoom setting). And I have a mashup map showing all markers from all page/post maps, but the map is also zoomed to show only one marker. I need to override the default zoom setting on this one map to show all markers. Preferably it would show the closest zoom possible, while still making sure to show all markers.

Since the default zoom and per-map zoom are existing options, I figure this has got to be close to being integrated into the shortcode...?

Thanks very much for any help or feature addition :slight_smile: