A chinese realase of the 1.9.1 firmware for Max, Max Carta, N96, M96 and several other models seems to be available on Baidu. Download links are here
http://www.sohu.com/a/258449995_99949461
and here
https://kknews.cc/digital/jbpmepe.html
Actually I don't have a pan.baidu accout, so I can't download the files. Any help for this would be much appreciated.