Currently obtaining/keeping high resolution (submeter) GPS data from the Trimble DA2 antenna (likely other brands as well) only works with Fulcrum on Android devices (https://www.fulcrumapp.com/blog/location-accuracy-external-gps-devices/).
I was informed from Trimble folks that a SDK (software development kit) from Trimble was now available to make this integration possible for all devices.
Please incorporate this SDK so we can collect the spatial and metadata in Fulcrum.