Hi, Microsoft's generic driver does indeed have a different volume curve than Comtrue's own driver:
View attachment 180297
Reasons for using Comtrue's driver would be:
-you want to update your 9038D's firmware
-you want to use the 9038D's native ASIO interface
-you want to listen to DSD256 recordings
Using the Tweak9038 Android App you can customize your 9038D's Minimum and Maximum volume to your liking.
With it, you could make it so that volume 1/100 in Windows is exactly as quiet as you'd like and 100/100 is exactly as loud as you need.