StarTools is display-device agnostic, but can be configured to display its GUI at a 4x higher resolution to accommodate high-DPI devices and 4K displays.
To enable this mode, create an empty file called 'highdpi' (NOTE: without extension or file type) in the StarTools folder where the executable is launched from.
Alternatively it is also possible to have StarTools to max out the available screen real-estate by performing the same procedure, except with a file called 'largeui'.
You may have to configure your operating system to not scale up StarTools. Wayland users may be interested in this link, while Windows 10 users may be interested in this link.