[microtonal]

There are no good options for languages or VMs on Qt in the Java/C#/VM/Jit range of the language performance spectrum.

Qt had pretty good Java support with Qt Jambi. But nobody cared and they cancelled the product.

https://en.wikipedia.org/wiki/Qt_Jambi

[sime2009]

alas, there have been many attempts over the years for language bindings even to interesting targets like the JVM and mono/.Net, but none of them really gained "escape velocity", except for PyQt (which is great might I add).