I think I've laid the foundation for supporting Qualcomm modems with ofono (committed to the pmOS repos.) My device has a vendor kernel, and I helped someone else with a mainline kernel. I haven't seen much movement other than that, maybe due to lack of interest or skill in potential developers. (Each device needs a few custom bits like firmware packaged.) Another problem might be a lack of usable GUI to actually use the modem features, but I'm not up to speed on recent progress.