I’ve just got a Mini 4 Pro and have had one trial with waypoints and I am a bit confused about the outcome!
Is the traverse path from one waypoint to the next the same as that taken when setting the waypoints (I.E. getting the position just right etc) or is it, as I suspect, calculated at the time of the mission dependant on the start and end point?
On my trial it seemed to be a mixture of both but the British weather prevented me from trying again from scratch, and other commitments have got in the way of getting out again! Grandchildren are a joy but …!
TAI. 
You set the start, intermediate (if any) and end points (amongst other parameters) when creating the mission and decide what the drone does when its completed it. It should repeat the mission (if saved) using the same gps coordinates and altitude etc regardless where you choose to stand (the home point). The only thing I’m not sure of is how the altitude is determined by the drone at the 1st waypoint relative to where you TOAL.
@D0c.Col Thanks for the reply.
What I was wondering is that, if I’m wanting to, say, fly through an arch, and I set the ‘entering’ waypoint, then fly over the arch and set the ‘exiting’ waypoint, will the drone, when flying the mission, fly through the arch following the direct line to the ‘exiting’ waypoint, or over the arch as was the case when the waypopints were set?
If you see what I mean! 
I’ve had a few glasses of wine whilst reading this and I got lost after the 1st over the arch bit. 
I’m not sure I would completely trust the acuraccy of the recorded missions enough to fly through an arch (depending on the size of its radius of course). It"s like landing a drone on its home point mat it doesn’t always work!
Also I’ve heard missions with tight turns in them sometimes bugger up the flight trajectory somehow and it all goes wrong. 
Theoretically though the waypoint parameters include the drones altitude so as long as they are the same on both sides of the arch and you got the angle straight it should just go straight through! Loss of signal could be an issue though.
Practice between rugby posts with your finger hovering over the cancel button as an experiment, preferably when there’s no match on!
The mini 4 pro has the option to continue the mission on signal loss 
Yes if you set it in the menu. 