since the saddles can be huddled together side-by-side, looks like you can go all the way down to 14mm. or add another saddle and make the bridge a narrow 6-string bridge.
dimensions appear to be slightly bigger than the schematics on the kahler site.
at the risk of looking goofy, i don't suppose you know what exactly the hex screw next to where the string's ball-end anchors does, do you? not sure if it's a locking screw or a screw used for slight adjustments to intonation...