Wait, you're using C#? Godot supports that! You can probably port Veado easily to it!
Focus on PROBABLY. But considering it's a smaller scope project, it shouldn't be that painful to adapt it.
Someone made another png avatar app based on godot. They have some interesting stuff (and proper linux transparency support <3 ) but there's a lot of weird stuff in it and only one sample. I really like Veado better and am planning to properly support mini with a purchase since the full version isn't out yet. I just like the things you did better.