When I load my savegame, open the script-editor and the script-task statistics - it's great to see how the number of running spacefly scripts goes down from 5000 to 0 in some seconds!

THANK YOU VERY MUCH!!!
I think it is worth to mention, that, after this clean-up a new save needs to be done, then close X3AP and delete the just generated x3story.obj from L, but otherwise you never will find any spacefly in game any more, because they destroy themselves immediately as long your modified x3story.obj is used.
So after this cleanup the player either needs to generate a new modified version of the game with your modified create_ship command or with the bugfix for the installed mod-scrips like IR2.0
As you reported in the other thread, the increase of FPS in normal play ist not so big - I just got 2-3 FPS after deletion and reload. This is much less, when I deleted 5000 Spaceflys which are not in sector NULL, but in "normal sectors"
But the gameplay in sinza and during battles should have a benifit of this deletion.