I doubt the server takes any of that in mind.
I think FS2020 app does all the retrieval calls. First by checking whether it’s in the manual or rolling cache, than requesting that block of data from the server.
FS2020 in the cloud is basically copy of Bing Map Data, color corrected and with meta data attached provided by Black Shark AI, as well as road network, river/water polygons, and forest / land use polygons.
The data comes in different levels of detail, same you see when you zoom in on Bing Maps. You can easily spot this in many places where seasons don’t match up between different detail levels. Flying high you mainly see sat data, flying low you get the high detail aerial photography.
Since it always starts with the low res sat data, you will just see that if you fly too fast for your system to retrieve and process all the aerial data.
What I have also observed is that your system generates the ‘missing’ terrain locally. The server might say where the ‘holes’ are, but looking at the difference in impact on my system, it’s definitely your PC that does the generic terrain generation when there are many clouds captured on the aerial imagery. Same as your PC generates the actual houses and trees (the server sends what goes where, your system creates the objects)
FS202 in the cloud has no intelligence, it’s just a big database. All the intelligence went into creating that database. Your system decides what to show, and thus what to retrieve from the cloud.
The app on your PC has the difficult task trying to keep up, building the world around you as you fly. How it does this is likely with a lot of asynchronous calls, tile based. There doesn’t seem to be a set pattern to how the terrain updates around you, more like ‘easier’ tiles appear first, finished first. Trees appear later. (I’ve landed on airports, then after coming to a halt, trees suddenly fade in all around me)
This also explains the ‘grinding to a halt’ problem FS2020 has on slower systems. The app keeps calling for more tiles as you move along, yet when it can’t keep up, you get more and more pending tile requests, memory use increases, page file gets busy, things slow further down. It’s seems to be lacking an ‘abort’ call, to stop generating stuff you’ve already left behind.
When I run into this problem I can either pause the game, wait for it to catch up and properly dispose of the tiles that are already out of range, or reduce terrain detail to minimum (10) for a while. That decreases the workload while flying on, giving the sim a chance to finish what it already started and clean up. When memory use is back down, I can set it back to my regular setting and everything looks fine and runs fine again.
It’s all in draw distance (terrain detail), altitude and ground speed.
Higher draw distance = more work (terrain detail x 2, doubles the area retrieved, 1.41x draw distance)
Higher altitude = less work (You can see further, yet the lower detail sat data is much less work)
Higher speed = more work
CPU limits how fast your system can generate terrain
RAM limits how much terrain your system can handle
GPU limits what final detail level you can display
Different planes have different impact on performance as well. Faster planes tend to have more glass cockpit instruments which are a resource drain, taking away time from terrain generation. Setting the glass cockpit refresh rate lower can help. The travel speed is the biggest difference though, 80 knots or 320 knots, the latter requires the terrain generator to work 4x as hard.