Night and day difference here. SS of the same info as the last. Used the started from the same save I posted above.
That's one of those chokepoint setups that just depresses the AI 
Glad to hear it's apparently stable now, thanks for the testing
10/10 doesn't get depressed... it just throws thousands of ship at it until a Raid SS slips through unnoticed...
I've been tooling around with the sprite pool slider. Observations so far are good. I run smooth as glass with a 33ms performance profile @ 1000 pool. Memory has been fairly stable (although the time played is pretty low).
@ no pool and 500 pool; I notice slight hitching especially at the start of combats. Memory was staying low but the hitching made me bump it up.
@5000 pool, the game really acts as it normally has.
I tried switching from 5000 pool to 1000 pool and there wasn't a decrease in memory size.
Save and restart game with it set @ 1000. I was hovering at ~ 950 mem just keeping focused on one planet. Switching planets (main production planet) to start up SS production bumped mem up to ~1040 and it has been holding fairly steady since. I have noticed that the game sometimes drops some used mem, but it isn't frequent at all.
