I will have to try LVM. Thx wasn't aware of the app. I did look at the KML, and do see altitude change in the coordinates. I also found some forum threads that indicated the csv file just has the relative height.
I am sure you Googled LVM, but here is a link if you haven't gotten to it yet:
Litchi Virtual Mission
Very useful program when planning flights since you see the 3D route, with changes in altitude. I've caught more than one error right off the bat when viewing diagnostics. If there are towers, high line wires, tall buildings, or high trees along the route you should see them as long as you fly the mission route with camera facing forward for the first route test. It is a good idea to fly this test initially, before adjusting the camera for points of interest (POI), particularly if you suspect possible hard objects along the route of flight. You should at least observe remnants of objects, so watch carefully. I've run a test this way deliberately trying to run through highline wires and tree tops and was able to see enough to know there was high chance of impact in real flight! As you observed with the KML, you can also click on each waypoint to confirm what you have with reference to the ground and mean sea level altitude (MSL).
After you set up all the POI's and initial camera angles, uncheck the diagnostics box (Google Earth), and fly the mission virtually, you can then double check all your camera angles to see if they are doing what you want. You can adjust speeds to fly the route in the time you have, particularly important with Spark! Obviously you have to go back to the Hub to make and save any changes.
I've flown some missions virtually 6 or 8 times before I finally get the speed and camera angle combinations I want. Not too much horizon, subjects (POI's) where I want them, and a reasonable time buffer to ensure safe completion. Then just go out and fly the mission. Hard to beat the combination of the Litchi Mission Hub and LVM for pre-planning and knowing what you have to get it right the first time you fly the mission. You have much more confidence it will fly the route in the time you computed, and if the RC loses contact with Spark, it will simply finish flying the route and come back to where you told it to end the flight.
TS