Are you interested in write your custom engine, or have you run into the limits of Godot?
Kinda both, started to want more control over my rendering pipeline and way to get good performance.
Also, I wanted to still using OpenGL and some of the stuff from this game depends only in the Vulkan renderer of Godot that I could try doing in OpenGL myself
I'm also interested in write my own tools for a while too, I'm working on a asset packer first of all for the past months when I got some free time (I'm using C99 for it)