Placement and moving of the scenery elements such as taxipoints and projected
meshes causes huge constant spike in CPU and GPU usage (up to 500 ms
-100ms/frame respectively) and FPS drops to single-digits, as low as 2 fps and
the image of the moved projected mesh disappears until I release the LMB. On
the screenshot I am moving a big projected mesh covering the whole apron and
runway. This worked ok in SU11. The issue persists in 1.31.20.0. Link to the
project is included in private. 
Hi @ZdenniZ Thanks for the project. We are
investigating this and I will update you as soon as I have more information,
Regards, Boris
Hi Boris. Any news on this? The issue is the same in 1.31.21.0…
Hi Boris. SU12 release version is still suffering from this bug. Has this been
acknowledged or there is something wrong on my end? Thanks.
Hello @ZdenniZ and sorry for the delay, I’m afraid
there’s nothing we can do to change that at the moment. We tested in SU11 and
AAU1 and it’s the same behavior. The more elements there are, the higher
ressources it will take to refresh the scenery (when you are moving a point /
object …). Try reducing your graphics settings to see if it’s better (I got
25 fps minimum when moving a point). Regards, Boris
Thank you Boris. I nevertheless think there is room for improvement because my
scenery isn’t large at all and I can’t imagine how the system would handle
editing large-scale airports. What about the disappearing projected mesh
issue? When I move a projected mesh it disappears and reappears in place when
I release the LMB which makes it difficult to position precisely. This was not
a thing in SU11(although SU11 had it’s own bug - ghosting of projected meshes
as described https://devsupport.flightsimulator.com/t/5008). Was this
noticed during your tests? Thanks, Denis Z.