I have had luck with the Telit LE910C1-AP (Asia-Pac) which supports B28 too. It has RCM compliance and supports PPP which I have had working with the Mikrotik wAP-R. I have tried the other interface modes like RMNet, RNdis, MBIM and CDC-ECM but they don’t seem to elicit a response - we’ll have to wait for ROS7 for some of those. The module also supports GPS as well but I don’t think I’ll ever use it.
The LE910C1-AP is Cat1 but I had no problems maxing it out at 10Mbit down and 5Mbit up on Telstra. There are other faster Telit models but I have yet to try them. Contact https://www.glyn.com.au/ in Sydney or Melbourne if you want some Telit modules.