The main target of the Godot Engine are game developers. But Godot’s easy workflow and functional UI elements, makes it also a good fit for non-game applications. There are already some out there you may know, like Pixelorama, an Open Source 2D sprite editor.
It’s still the same essential issue. You only want to draw what has changed and only when it has changed.
Lowering the rate could make things look worse when they actually do update and cause unneeded redraws when they don’t.
I get not wanting to learn something else. But it’s a case of using the right tool for the job imo.