Huawei E3372 seems to be a CDCE device. /boot/loader.conf has to have a line if_cdce_load="YES". Only usb_modeswitch works with this one. Command:
/usr/local/sbin/usb_modeswitch --default-vendor 0x12d1 --default-product 0x1f01 -J
Device ue0 appears to be configured (with ifconfig -command). Using 'dhclient ue0' a network address is found and using the address and adding a default router the network interface is usable
Has anyone tried this? I guess it may be worth trying, but how do I backout if it messes something up?