Hi,
I think you can get any feature of BG96 including LTE B4 by using WisLTE module via BG96 AT command : AT+QCFG=“band”[,<gsmbandval>,<catm1bandval>,<catnb1bandval>[,<effect>]]
http://docs.rakwireless.com/en/Cellular/WisLTE/SoftWare Development/Quectel_BG96_AT_Commands_Manual_V2.0.pdf
Please try it.