I never used MC (not very much into TUIs) but ages ago I wrote a graphical file manager in the same vein. For me the inspiration came from Directory Opus [1] on the Amiga, which was just awesome.
When GTK+ was released in the late 90s, combining my love of C programming with a newfound home in Linux and GTK+'s ability to make complicated graphical interfaces resulted in a dual-pane file manager. It was a great project.
I find it a little sad that you haven't released a new revision since 2016 [0]. It has not declined in usefulness.
Edit: Incorrect:(I'd guess the biggest requested change would have been to update it from using GTK 2 to GTK 3, but I can
definitely understand why someone wouldn't want to...)
I thought I had released the GTK 3.x version, but I guess not, then. It might have been that there was something I just couldn't get to behave right, gentoo is somewhat picky about its UI and tries to make it do the right thing in ways that GTK sometimes isn't ready for.
Today I guess the target would be GTK 4.x, I tried to align with the latest main version back when I was maintaining it more.
Oh and 2016 makes sense, had my first kid in 2015 ... :|
When GTK+ was released in the late 90s, combining my love of C programming with a newfound home in Linux and GTK+'s ability to make complicated graphical interfaces resulted in a dual-pane file manager. It was a great project.
[1]: https://en.wikipedia.org/wiki/Directory_Opus