Best 2D Mario frameworks on Godot?

[Disk]

Although it doesn't seem to be exactly what you're looking for, there is something called MarioTool that is still a work in progress, it helps create games in the style of smb1, specifically its all-stars version. I can't speak of it's quality as i haven't used it myself however. Hope this helps!  

(The itch.io page can be found here: https://xpoxy.itch.io/mariotool)