I am gonna pop in and share some observations I’ve had here in the Hugo community.
When Bjørn implies things like, “the roadmap is in my head”, or “I work on things that interest me”, it isn’t a wall going up around development, it is modeling how one should approach the project. If you want to work on an API design proposal, that is in your head, and of course it is worth it.
But you gotta scale it to a community free software project. That means, iterate, discuss, iterate, reveal, that kinda thing. Check the #dev forum, or the issue tracker for a sense of how decisions get made.
The other thing is, no effort is punished. This depends on my prior statement about iteration. No one wants you to spend a huge amount of time working on something that runs counter to the direction of the project. But folks working to scratch their personal itches is a driver for Hugo development (and arguably any FOSS project).
Bjørn is the only devotee. In all likeliness e reads every post on these fora. That means if you want eir involvement, you need to get as many folks as possible excited about your idea. But a much better way is to take the initiative, do as much work as you can on your own, and then ask for assistance when you hit a wall, so you can continue on your own. Folks here will rally to help someone learn in order to improve themselves and the project.
If you are excited about a web editor that can plug into Hugo in a “native” way that assists in content creation, no doubt many folks will have input for that. My advice is to go for it, figure out an MVP, and post it for feedback.