Something to be aware of: very recent versions of Windows support "per-monitor DPI awareness", meaning that separate displays can use different logical pixel densities; previously, all displays would use the same logical pixel density. Perl/Tk does not support per-monitor DPI awareness on Windows, and I believe adding support for it would be difficult. Rescaling (fuzziness) will be observed for Tk programs when toplevels are moved between displays with differing logical pixel densities. One issue encountered in upstream Tcl/Tk (and which likely affects Perl/Tk) is that this rescaling is not done correctly for overrideredirect toplevels (https://core.tcl-lang.org/tk/info/a9ee44102b); it is not clear if this is due to a Tk bug or a Windows bug.