What issues make you too scared to play with the main save?

While it is not necessarily my main save per say, the save file is an important one.

Long ago, I remarked on a savegame of my sim Yopson, on the old forum.
At last check, he had close to or around 150 children  [some of them already dead]. The latest pack has almost certainly corrupted various aspects of that save file, for a variety of reasons.

1. The amount of children he has is quite likely why the game hangs in saving/transitioning from his lot to the world view. 

2. I'm not using that many mods, but again, the latest pack did some weird stuff to eyes, so theres at least one eye mod I'm unable to use for sure. Certainly likely that it is one reason the game tends to randomly hang with saving or transitioning to worldviews.

3. The number of packs the game already has; I've certainly disabled the dust pack, and as I write this, it does occur to me that I cou;ld certainly attempt to experiment with disabling the latest pack through the settings. My main point here is that the game is reaching the  theoretical maximum area of packs it can handle and the devs need to  look more at revamping older areas with better stuff.
To be fair, my system is fairly old, over 7 years old now, but it runs most games okay [starfield runs on it...].

But my main point is that I dont use very many mods at all, but I think because I have tendency/pref to play very long running save files in terms of time, the game tends to balk at that.
Various solutions and workarounds....

One thing I might try is a saving of the main household to library after roughly each in game week played. My main save has vampire whom I've played since... 16 or 17, and I have little issue loading her save, but I still am thinking that a household back up every so often is a good idea

I've already said that I don't run many mods, but the custom eyes I use are very precious even if they were updated 4 years ago at last check. I believe the complexity of some of the eye mods I use tends to determine if the game hangs or not, because with Yopson savefile, the probably cause of the hanging there is relatively easy to guess.

All the children's various genetics...

Likewise, some of my other games, while I haven't played them too long, its more the complexity of the genetics meshed with the mods that weirds the game out.

There are other possible ways to get around these issues too...

Deleting most of the houses on the many of the lots in the game could help along with deleting the evicted sims. Certainly one could also just let the sim run and cause most of the sims to die off, allowing one to redecorate the hoods to desire.
Settings the population to something doesn't let the game push any sims in.

As it has been said, back up saves often. I have, or did have, a back up in 2016, which was almost too old for the current game to use [a lot was weirdly corrupted so I trashed those saves]. But I still extracted my sims from those games that I could, yeah I have back ups for 18 and 20 and as recently as this past summer or so.

The problem is that similar hanging happens on some of those saves even from the recent back ups. So yeah, I still think that much like the ancestor, Sims 4 is getting too bloated with all mannr of packs and they need to pause and beef up the game core more to handle what I think are the main reasons for the game engine choking.

More complex genetics, especially with CAS mods and who knows how many generations of sims.
Long played save games have a complexity to them.

More robust game engine so it doesnt crash, but instead goes to main menu with popup "Game failed to save, possible corruption". Something like that anyway.

Apologies if this post doesnt quite stay on the one topic, but there are those who have multiple "main save" files and such, just commenting on what I've experienced in the past couple days and how I've tried to think about it and work around the issue.