Ground unit, Diversity and Burnout protection

Hi,

Am I correct in assuming that the herelink uses antenna diversity with both ground station and air unit?

Also, is there a burnout protection on the ground station side?

Can I use the ground unit with only the omni-directional antenna for a period of say, 15 minutes without it damaging the ground unit?

Is it safe to have no antennas connected for a brief time (under 30 seconds)?