Thanks Gary.
In my case, I'd like to photograph a wall from top to bottom in overlapping rows. If I can edit waypoints externally, then I can quickly set up repeating camera paths from just two or three base points. For instance, if I can fly to the upper left and upper right corners of a wall (at ~10m elevation, let's say), then it's easy to leverage use those two valid GPS points in order to automatically create a mission plan where the drone moves back and forth from the top of the wall all the way to the bottom, since only the elevation changes each row (decreasing each row until 0).
There's nothing stopping me from manually setting dozens of waypoints in Tower, of course, but it's a little tricky because Tower shows a plan view of the map, so that the waypoints for a wall will overlap. I don't think there's a way to shift orthographic views in Tower from plan to elevation.
Unless we can also export waypoints, the question then becomes: how do we prepare these external waypoints so that they correctly relate to the maps in Tower? My fear is that the imported waypoints won't relate to Tower's implict coordinate system and the drone will consequently fly into walls, or worse.
It's great to hear that we can import waypoints, even so. Does anyone have an example of doing this? If so, how and by what were your waypoints generated before importing into Tower?