Hi Ivan,
Yes, we agree that the micro-usb 3.0 connectors are very fragile and they have given us much grief. We have recently introduced a locking cable for newer BB60s which has a similar effect as your solution. The locking connector unfortunately cannot be fashioned onto older boards as it required a slight board redesign to make room for the new end plate. We are examining the larger USB type B connector for future designs.
Regards,
A.J.