When spawning large maps, especially those derived from demorecords, be very very liberal in applying FILTERS.
Imperial City will get about half spawned before your client crashes.
HOWEVER
Ignore doors. Ignore Cars. Filter out 75% of critters named NPC... and you'll get further.
The client will crash because the server used to remove objects outside of a certain distance... our client can't do this by itself. Even if it could, because my spawner spawns by YAW (mentioning this because target_custom_far alive could give you the furthest target with selectanyentity 1) it wouldn't matter. The objects would have to spawn by sequence, and when you went to that far area your spawns would be gone anyway.
SO!! FILTER FILTER FILTER!
HMMM... may make an algorithm to calculate creature spawnables! Also might test on varying computers to estimate max spawns.
Then with a must include list... yeah. Slightly less popped maps may be possible if I can get a fairly accurate read on maximum objects on a map in the client.
Yeah. Full research is out of scope. I go back to work Monday
WHAT I WILL DO though is add a master filter variable. That way every object will be rolled for. So spawn 50%, 75%, etc.