USB gadget g_multi and Windows host

Hi,

I was trying get the BBB (jessie, kernel 4.1.10-ti-r21, rcn-ee.net console Debian Image 2015-10-09) working as USB mass storage and network gadget using g_multi:

modprobe g_multi file=/var/local/usb_mass_storage.img

This works fine for Linux hosts, but Windows fails to install a driver. The problem is apparently that both modules usb_f_rndis and usb_f_ecm are configured in the kernel:

from https://www.kernel.org/doc/Documentation/usb/gadget_multi.txt:

The only thing to worry is that the gadget has to have a single
configuration so a dual RNDIS and CDC ECM gadget won't work unless you
create a proper INF -- and of course, if you do submit it!

Is there a reason why both modules are enabled? Could usb_f_ecm be disabled by default so g_multi SHOULD work for Windows?