Pop growth calculations causing excessive lag?

[XavierMace]

I'd previously made a post about performance issues and finally figured out that the primary issue I've been experiencing seems to be pop growth calculations.  Not the pop count itself, purely the pop growth calculations.  To be 100% clear, this is with an absurd level of pop growth in my empire (organic growth+organic assembly).  Galaxy is at about 8k pops, my species is 2k of that.  I was getting a solid 30+ second stall on Day 6 of every month.  I know I've played games in the past with higher pop counts and not nearly this bad of performance.   Gene-modded pretty much all the pop growth traits out of my species, destroyed/disabled other sources of pop growth (buildings, edicts, etc), enacted discourage growth decisions on planets but left pop counts as-is.  Way late game tech, so that means I've still got a fair amount of growth.  Stall instantly dropped down to just a couple of seconds.

 

I'm aware of pop count affecting performance, but I don't recall ever seeing the growth calculations themselves being blamed for major performance issues.  Is this just old news that I've somehow missed or are other people not seeing this issue?