Thanks. As you said, the IDE is built on winforms, so it's windows only. maybe it was a mistake to not to use a cross platform framework like avalonia, but i really like the winforms designer, and winforms is the only UI framework i ever used, except for MAUI which is not a good idea to build an IDE on.
Windows.Forms is becoming less of a problem with projects like LibreWinForms [0] progressing quickly. I just tried to build your project and there are only a few classes that are not implemented when it comes to the GUI.
I really miss working with WinForms.
Every other UI framework I worked before and after always left me with the impression that something was lacking, in speed of development, fast iteration, but also in the quality of the abstractions.