text is blurry on hi DPI (e.g. 4K) monitors

[captainmidnight]

I just bought a 27 inch 4K high DPI monitor.

My operating system is Win 7 Pro 64 bit.

I set that monitor to its full resolution (3840 x 2160), and then set a custom scaling factor in order to make GUI elements appear correctly sized. (A 27 inch 4K monitor requires 170% scaling in order to make a 3 inch ruler in the Windows scaling dialog measure exactly 3 inches with a physical ruler.)

At this point, operating system programs (e.g. Windows Explorer) appear to display correctly, with super sharp text etc.

Unfortunately, I have found that Core FTP displays with fairly blurry text.

This is true even after I upgraded to the very latest build 1912 LE (free) edition.

From what I have read, this happens when developers built their Windows GUI applications with old Microsoft APIs, as they have new APIs that are supposed to scale perfectly with modern high resolution displays.

Is that the case with Core FTP--that it needs a GUI overhaul?

Or, did I miss some setting in the program that will cure this?