Yes forgot to add gliders making out of airfield landings , I should know I fly them every week during Summer
On Flarm , first it is not a certified system , cannot be due the frequencies it uses, so cannot be mandated ( dixit EASA) but secondly what can you do at 100 Km/h or more against a drone ? The drone has to avoid you , not the other way around. The detect and avoid technology must (and will) be in the drone .