Just to give you an update:
Yesterday i did a 14,4km flight with the OpenLRS (telemetry off) and it worked fine (no fail safes).
Eagle Eye flying wing (1,6m) with 2x 3000mAh 3S
ImmersionRC DUO5800 v3 with 7,5turn Helical and ImmersionRC Tx 5.8Ghz 600mW with SPW
Turnigy 9XR with Hawkeye 1W OpenLRS (SRH771 antenna on the Tx, selfmade dipole on the Rx)
At first i was not sure, if i should continue the flight, because the picture quality was pretty bad from 4 to 9km.
When i reached 10km, the picture got better and i kept flying till 14445m. I needed to turn back, because of the battery voltage. On my way back the batteries died in ~4km distance, so i decided to land the plane on a field that was in line of sight and 3km away.
It worked perfectly and i picked up the plane by car. On my way to the field, i was also able to test the nice PMR radio beacon feature…it worked very well (although i already knew, where to go *g*).
The flight was done without telemetry or RSSI or autopilot, so i can not tell, how much RSSI was left in 14,4km, but as i will not need that much range anyway, i will try to reduce the OpenLRS output power next time.