HiDPI

MusE uses the Qt framework which has a fairly good support for HiDPI screens. So the MusE application itself should be scaled automatically, according to your screen's DPI. If it doesn't (e.g. the monitor is not properly recognized or your desktop uses wrong presets), you should still be able to set an appropriate scaling using the corresponding environment variables. See Qt HiDPI settings for more information.

The typical problem with HiDPI (which affects all existing Linux DAWs) are the native GUIs of the plugins. They use different UI technologies, many of them are old and hardly any has a proper HiDPI support. Qt normally opens the native plugin window with the current application scale factor, which can lead to ugly effects as most plugins ignore this setting.

To cope with these issues, a new parameter exists as of MusE 3.1 (Global settings -> GUI tweaks -> Revert native GUI scaling in HiDPI). When set, the size of the native plugin window is explicitly adjusted to fit non-scaling plugins.

As the behaviour of the plugins can be very individual, there is a possibility to override the setting on a per plugin basis. This can be done in the Settings found in the generic plugin GUI.

Some plugins ignore the window size set by the caller (MusE in this case) and resize their windows uncontrollably.