I have forgot the distance that the fc40 needs to be away from you before activating RTH. Going out in the field in the morning to try a few different things and cant remember how far away the 40 needs to be away before RTH can be activated.
you can activate RTH or failsafe at any distance. But if flying in homelock home lock will not work unless its 10mters or more away from you and will go in to course lock if closer then 10m