Watch the current, the EC5 is rated like the XT90 and can handle more current than the XC60. If the helicopter for some reason draws more current than the XT60 can handle, the battery will provide it possibly overheating the XT60 and other...
Ultimately satelite or cellular will be the only way to extend range to basically unlimited. The current "line of sight" protocol is great but will always be limited. But this opens up other considerations, safety being foremost. There is a...