Surprisingly the 3G/4G seems to not be an issue with the stock antenna (narrow enough band filter?)
Agree with the 7x12 that is what I am testing at the moment.
Tried a combined GPS/GLONASS - 4G antenna where the GNSS antenna was stacked on top of the cellular antenna but it was poor.
@DaneGer21 The one you point out is a GPS antenna not sure if it has the bandwidth for GLONASS as well. JUst one Q for drone deployment if you have a compass on your drone do you really want a magnetic mount on your gps antenna? If no compass, not a problem.