I have an Intel HD graphics 5500 adapter and a resolution of 1920x1080, which is the maximum for my Windows 10 laptop and I use an extra DELL monitor.
I have set the scaling ("Change size of text, apps, etc.") to 100%.
However some things appear quite disproportional.
For example my Winamp is either really tiny when I am extending my screen to my second monitor or normal sized but his expanded playlist humongous when using the second monitor as my main display with my laptop lid closed.
Scrollbars are really fat and icons in SQL Management Studio are tiny, buttons small and clamped together in ways that make text hard to read, etc.
I tried smaller resolutions, but the effects were worse.
I tried updating my driver, but not only is the installed version a higher number than the latest on Intel's support site but also it failed when I tried to install it saying it's not compatible or something. And, yes, I did triple-check I am downloading the correct driver. Zelda
I also have an AMD Radeon R7 M270, but I guess it's an integrated adapter that I am not using (and would prefer not to).
It appears the scaling changes each time the user logs in. Sometimes some items are disproportionate, another time others.