(I think this thread was about a different, older copy dialog in Opus 11 where some of the less important numbers used a smaller font. That's no longer the case in Opus 12. The issue it was about no longer exists.)
The dialogs do respond to scaling, and the fonts should be the same size on any monitor, 4K or otherwise, provided the OS's DPI scaling is configured properly and not being overridden.
This is from a 27" 4K screen at 200% DPI scaling:
If the fonts are really small, as in half the size you expect them to be, then there is a DPI override in effect via Windows compatibility settings applied to dopus.exe. You want all overrides turned off. See Windows Compatibility Settings / Wrong DPI / Installer misdetects OS for more detail.
We'll be making them fully configurable in the future, as well as defaulting them to the newer standard 9pt size rather than the older standard 8pt size which Windows used to use. But they should already be a readable size unless something is misconfigured in the OS DPI settings or compatibility overrides.