Personally, I think the Freeflight is an awful piece of kit - it takes user-unfriendliness to a new level and trying to create WPs from L/L or grid is just painful, let alone linking them into a FPLAN. Ous doesn't have the DR option (possibly disabled) but gives alerts on the ND if the GPS signal is lost.
I guess Trimble never thought to include a pilot in their design team for this one!