[glorang]

For info, in usb_modeswitch.conf you can find:

# If the configuration for your Huawei modem uses the standard switching method,
# you can globally set an alternative method here which provides a different mode:
# either plain serial PPP (for older modems) or NCM which integrates nicely
# with recent Linux distributions, possibly avoiding configuration through a
# modem built-in web page. All other modems are not affected.
# Available as per-device parameter 'AltHuaweiMode'

HuaweiAltModeGlobal=0

But the correct parameter is HuaweiAltMode and not AltHuaweiMode. Apologies if it's nitpicking, it might save someone else 15 minutes of their time in the future.