It seems that you have to use the Caesar 2018 for this situation.
The API module in Caesar 2018 does not limit the multiplier.

See also:

http://forums.coade.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=75175&Searchpage=1&Main=17284&Words=%2Bapi+%2B617&Search=true#Post75175