@SolarBarn, have you been able to test your phone vs drone vs L1/L2 GPS? From my understanding, cell phones use assisted GPS (A-GPS) whereas their signals are assisted by triangulation from cell towers. This means that the coordinates will not be true WGS84 and will not match the drone even if it were more accurate. You can turn off your cell data temporarily though… I’m not saying that this isn’t a good option for them though.
Newer phones actually run dual-channel L1/L5.
I would recommend the Precision GPS app for Lat/Lon and GPS Averaging for elevation. The only reason GPS Averaging is good for both is it rounds the lat/lon to a tenth of a second, but Precision GPS doesn’t provide elevation unless you buy the Pro.