Finally, just as I had almost quit searching, I found a post on Adobe's forums which helped me solve the DPI awareness issue.
My Solution
1) Right-click the Adobe Professional DC icon on the desktop.
2) Select Properties from the drop-down.
3) Select the Compatibility tab in the Properties dialog box.
4) Select the checkbox next to, "Override High DPI Scaling Behavior."
5) Select the "System (Enhanced)" option from the "Scaling Performed by" drop-down.
Note: this solution worked for both the Professional and Reader versions of Acrobat - the icons and dialog boxes are larger on the laptop display as well as being a usable size on external displays.
Figure 1 Dialog Box Selection: Properties, Compatibility, System (Enhanced)
The Issue
My issue began with the purchase of a Windows 10 laptop with a 4K Ultra HD (3840 x 2160) display.
On this laptop, I found Adobe Acrobat Professional DC to be unusable as a remediation tool. The icons, text, and dialog boxes were too small to use on the laptop display and when the application is switched over to an external monitor, way too large to be used.
I contacted Adobe support. They immediately responded and offered a download of a "fixed version" of Acrobat DC Professional for this issue. While the fixed version helped a little bit for the laptop display, I found the dialog boxes for editing tag attributes unusable - the text collapsed on itself. The tag tree plus signs had too small of a click area to be used at speed. Also, the application could not be used on external monitors.
I had been directed to Dan Antonielli's excellent solution page but could not get the manifest solution to work for me.
The Post leading to my solution
I searched again today for a solution and found one in the Adobe forums, https://forums.adobe.com/thread/2011583.
NTConnections had posted a reply on Feb 9, 2017, "Seeing as how this is still current, I wanted to share my feedback from a call with Adobe. After about an hour with them on the phone we were able to resolve the issue: Right click on your Adobe DC icon on the desktop, click Properties, click Compatibility, Uncheck 'Disable display scaling on high DPI settings'..."
This post inspired me and, while I did not have the "Disable display scaling on high DPI settings" option, I did have the two-step selection option mentioned above.
Thank you NTConnections!
Thank you Adobe Forums!