OK I just played 2 sessions over 40 mins with the above settings, seems OK.

Actually that was a one-off, it crashed again... This time after about 15 minutes.
I can confirm that my GPU is not getting hot, I had a temp monitor open on another screen and the GPU was only ever max 60 degrees or so.

Good news! I went one futher and did the following:

1. Uninstalled DayZ
2. Deleted my C:\Users\<name>\AppData\Local\Dayz folder
3. Reinstalled DayZ on C:\ (M2 HDD), was previously on my D:\ (A SSD but not M2)
4. Went into my Nvidia control panel and 'reset' any profiles I had for Dayz.exe
5. Kept the default in-game settings the same as default (didn't change any in game settings)

Hi Geez, I just played vanilla Chernarusplus on official, for 45 minutes, no crash, exited fine. Seems to be just Frostline, crashed each time.

Here are my dxdiag outputs and DayZ appdata folder, zipped, as requested.

To add: I actually kept real time protection ON, but disabled "controlled folder access" (below it) in windows settings. Hope this helps someone!

I FIXED IT!!
It was windows antivirus, when I went into it's settings and disabled "real time scan" it made the DayZ folder in Documents, and saved it. I will add dayz to be ignored by windows antivirus and I should be OK.

It's also worth noting I get an error sometimes when I close DayZ now (even when it was on D:\) it says 0x0000005 STATUS_ACCESS_VIOLATION
in a little window when I exit most times.

I completely reinstalled Steam (And DayZ), on my C:\ this time (where my OS is installed), last time it was on my D:\ which was for apps/games.
Still not saving.... Wow.
No "DayZ" folder in my Documents folder still. I have no idea what to do this is frustrating.

Do you think uninstalling and reinstalling Steam & DayZ might fix this?

And no I did not change any rights besides password login.

Yep my account is 100% an admin account, and the only account on the computer. And yes in the security tab it says my username has ownership of the Documents folder.