Hey!
Fintech dev here, who is also tired of that sh*t! (10 years business sw dev exp, plus 2 years unreal, 1 year unity, using godot lately)
Last december I've put together a custom dialog/VN system for my collection of reuseable game module library (also did inventory, menus, and other small things, and working on a moderately detailed rimworld-like character sheet+progression system right now). The only caveat is that I'm working with the C# version of godot, because that's the language I known for a long time.
Usually my weakness is the UI and visuals, so most of the things i do/draw is ugly, but functioning well :D
Your link doesn't seem to work, so I don't have much material to base the idea on, except the description... by that it doesn't seem to be complicated. There are some really good vn plugins for godot, but i prefer to go custom, because the flexibility, and a lot of code people share are just plain bad imho (by that i mean they would not pass my code review).
Since this is an indie game, I don't really expect to be paid, but if you plan to monetize the project, I would like some revshare. In addition to that I would like to keep open the possibility to reuse the code I write for my own projects later. (Oh yea... I started out by making some small nsfw games (one of them is published here), because that's where the money flows, please don't judge based on that! :D )
Discord: indigopa