Help troubleshooting completely random freezes

[entei36]

So in the middle of a heavily modded playthrough my game has started to randomly freeze too frequently and i had to stop playing to solve this issue.
For context, i'm a moderately experienced modder and before starting playing i carefully and manually patched my entire load order with sseedit. 
I did every kind of test to figure out the cause but after 2 months of attempts i'm now at loss and don't know what to do.

I'll try to summarize the most significant tests and conclusions:
To identify the issue, the test i usually repeat consists in loading a save in the outdoors (cause apparently freezes only happen in outdoors)
and playing for some minutes until the game freezes. There are no specific actions i do, given that the game could freeze even if i stand still in the outside
These are the most relevant tests:
 

1) Freeze apparently doesn't happen on a new save on a mo2 profile without mods

2) Freeze does happen (though being very rare) in a profile with only 4 mods and the main save. Removing one or all these 4 mods from this test profile apparently doesn't produce the freeze. 
   
   However, freezes do not occurr in a fresh save with the same 4 mods activated
   and removing these 4 mods from the main profile (with all other mods activated) still cause freezes

3) Manually deleting about half of the script instances in my save and doing several tests on the main profile didn't produce any freeze.
   However, after more tests, i wasn't able to spot a single script responsible

4) Probably the most significant: freezes did happen even at the beginning of my playthrough though they were very very rare and
   completely unreproducible.

It seems clear to me that there is not a single mod responsible (point 2) and that, by going on in playthrough, freezes likelihood simply increased (point 4)
The problem is that, due to its random nature, i cannot be completely sure that tests where freezes didn't occur weren't simply tests where
the likelihood of freezes was very low, and therefore i wasn't able to reproduce the issue.

I even used tools like Procdump to generate something like a freeze-log when skyrim hangs,
and despite it gave some interesting info i still wasn't able to identify a culprit. I could share the logs (they are quite heavy)

My best guess actually is that the issue is related to some game engine memory management, and it is partially related to the savegame.
If anyone is willing to give even some suggestions or things to do i would be very grateful