Windows 10: How do I set different DPI scaling for different monitors, and KEEP it

I have a Surface Pro 4 running the latest update of Windows10, and a LG Ultrawide monitor.

I have set the display settings manually, and I have reviewed them using the regedit -- and everything works fine and I'm happy with the settings: I have the Surface Pro display set to 200%, and the LG Ultrawide set to 100%, and it's fairly copacetic.
My problem is, every time I restart my computer, I have to "Turn off custom scaling and sign out" and manually restore these settings. It's maddening, because I'm docked and use the same monitor every time.
How can I keep Windows for defaulting to the 'base' Surface Pro scaling of "200%" for both monitors, and keep my monitor-specific settings?

Solved: Change DPI Scaling Level for Displays in Windows 10 - Page 7 - Windows 10 Customization Tutorials

:)

 

Mixed resolution scaling results in blurry applications?

Yes, you can turn all the DPI scales to 100%. Programs that you drag over to another DPI screen may appear to be a different size (in terms of how much space it uses on the screen when you measure with a real-world ruler), but they will not stretch/scale
and thus will always look crisp.

For background info on this, I have an article that may interest you:

DPI Scaling in HD Multi-Monitor Configurations

 

Multiple Display Size for "Select and Rearrange Displays"

That's because the displays are different densities (number of pixels-per-square-inch, also known as DPI or Dots Per Inch). Even though the monitor is physically smaller in real life, it has many more dots, and thus it appears larger in the preview graphic.

There is absolutely nothing you can do about it, you just have to drag the two monitor representations around with that understanding in mind. you can still make the monitors "touch" in different spots, but the pixel dots have to line up.

See DPI Scaling in HD Multi-Monitor Configurations for details about how to do this, including
a video that demonstrates it towards the bottom of the page.

Okay maybe there is one thing you could do about it: buy monitors that all have the exact same number of dots-per-inch, and then you'll never have this issue.