Thank you so much for this! Nvidia has a similar setting which I completely forgot about and it does wonders for sharpening the image.
For those with Nvidia cards, open the Nvidia Control Panel (Right click Nvidia icon on system tray -> Click Nvidia Control Panel)
Then go to Manage 3D Settings and change the menu from Global Settings to Program Settings.
Look for AOE3DE under the list of programs. If it isn’t there, click Add and navigate to your its installation folder and select its executable.
Now set Image Sharpening to On first and then in to 1.0 in the menu that pops up. You can play around with the values as it suits you, but I found this to work well for me.
SenorSmite - you, sir, are a legend.
Edit: A link to a post showing comparisons between the sharpened and unsharpened game