So, sometime around the last official CA patch I started experiencing a lot of stability issues with crashes, virtually all of them occurring during the end of turn cycle, and the majority of those happening right at the end of the CPU turn cycle; in other words, after the last faction moved but before the next turn actually started. I spent a ton of time testing basically everything I could possibly think of in terms of both modded and unmodded setup to resolve this, and the only consistent fix I have found is related to in game graphics settings. This leads me to conclude (soley through my own experience, not an Officially Endorsed CA Solution) that the issue is likely something with the vanilla game itself. This includes duplicating the issue inside a fully vanilla install until I tried the below fixes. Once that worked I began using mods again in batches until I'm now pretty certain it's no one specific mod that can be labelled a culprit, or at least no more so than during any other point in the game's history.

Anyway, if you've been experiencing similar, there are two things I have found to cut these crashes to virtually nil.

1) Set the end of turn cycle to the fast forward instead of watching enemy moves. This does provide some tactical disadvantage to the player as you can no longer see when enemy armies enter ambush stance, but I'd argue that was a somewhat unfair advantage to begin with. But it also prevents the game from jumping around and displaying more of the map which seems to be key in helping.

2) Basically I dumped most of my advanced graphics settings to potato:
TAA
Antriscopic 4X
Low
Low
Low
Off
On
High
Permanent

Low
Medium
Low
Low
Low
Large
2D
High

Again, all I can say is that this works for me. I highly, highly suspect it's some sort of internal Total War engine issue related to the amount of the map that has removed Fog of War, and that the higher that % of the map gets the more unstable your game becomes, but cutting back severely on the amount of detail seems to (again, for me) nearly totally resolve the issue.

Believe me when I say that I take having this mod collection be as stable as realistically possible seriously and the last thing I want is any of you to download this and then have your game blow up in your face, and I spent a lot of time testing everything I could think of only to reach the conclusion it's almost certainly a vanilla issue. Hopefully, I'm right about that and hopefully it is fixed in one of the future patches, but for now if you hit issues this should help.