I am in the processing of setting an Elite x3 and had a question about the second SIM slot on the device. I'm not sure if I will use it dual SIM mode often, but on previous dual SIM devices I know that the non-active data SIM would use 2G to maintain a voice/data/text connection. In the US, AT&T has shut down its 2G network. This has made the other Windows Mobile dual SIM devices basically single SIM in pratice now...
It looks like a firmware update on the x3 from late 2016 remedies this and allows the second SIM to use 3G in the background while primary SIM uses HSPA+/LTE. Is this the case now?
I was looking to see if anyone can speak from real-world experiences. I have a T-Mobile SIM with an unlimited data plan that I often use for mobile hotspot but also have an AT&T SIM I use primarily for voice and for data when in more rural areas without great T-Mobile coverage. When I'm using AT&T SIM as primary T-Mobile can still step down to 2G, but this is no longer the case when AT&T would be SIM2.
I'm not in a spot to test it out yet -- phone is at home and I am traveling this week.