Re "alarms coming from the wrong direction". Flarm uses true tracks not headings. On ridges with a high crosswind component and low airspeed an alert being indicated as being straight ahead may be from 30 degrees or more offset with respect to one's own glider heading. This was highlighted in 2007 in our Scottish Gliding Centre trial and should be understood and allowed for by users. There is no practical technical way to avoid that - not until we all have electronic compasses out on our wingtips anyway.