From my extensive experience, DDU does not stop Win 10 from overwriting and trashing a new driver installation, (if it does for you then that’s a great bonus). I have been using DDU for many years. The instructions with DDU clearly state that one should take precautions to stop this from happening from within Windows or by disconnecting the computer from the internet. Here is a link to those instructions. It may be that the instructions have not been updated and that you are perfectly correct based upon your experience and observations, and that is very likely! 
Anyhow CorduroyLight56, I trust what you are saying and I think we have a new simulator update today according to rumour.
TIP, some game boosters and Nvidia Experience can automatically update your drivers unless you check a box to stop this from happening!
Here we are, straight from the ‘horses mouth’ I hope this clears up the confusion around the capabilities of this tool, (the instructions may not have been updated of course). Below is a link to the instructions for DDU recommended usage …
Recommended usage
- You MUST disconnect your internet or completely block Windows Update when running DDU until you have re-installed your new drivers.
- DDU should be used when having a problem uninstalling/installing a driver or when switching GPU brand.
- DDU should not be used every time you install a new driver unless you know what you are doing.
- DDU will not work on network drive. Please install in a local drive (C:, D: or else).
- The tool can be used in Normal mode but for absolute stability when using DDU, Safemode is always the best.
- If you are using DDU in normal mode, Clean, reboot, clean again, reboot.
- Make a backup or a system restore (but it should normally be pretty safe).
- It is best to exclude the DDU folder completely from any security software to avoid issues.