Opus uses the system-wide dialog font, which it looks like you've forced to something custom and fixed-width. So you're already changing the font somehow (although we don't recommend using a fixed-width font, as I mentioned in the other thread just now).
If the system-wide font is too small to read in Opus, the same will be true in lots of other software.
The DPI scaling settings in Windows exist for this purpose and you should use them. They will increase the font size in DPI-aware programs (such as Opus), and scale up the windows of non-DPI-aware programs. If you're using a 4K screen and use 200% scaling then you'll get pixel-doubling of legacy programs, which generally looks good, as it doesn't blur them like it would with other scaling amounts.
Be sure to reboot after changing the DPI scaling factor in Windows, as a log of things do not completely update until you do so, and will be scaled and not look as good until then.