When to open source a new project?

I've been working on a side project for a little while that will be open source and I'm facing a dilemma. When do I go public with this and how do I get contributors?

At the moment it's barely functional but the idea/roadmap is all in my head. Rather than continue for months and throw something out there as V1 I'd be interested in gaining collaborators that can bring in new feature ideas, skills and keep me enthused, but I see pro's & con's for this.

Pro's

• The project spans multiple technologies, some I'm new to/rusty at so getting experts would help on this.
• Discussing ideas with others would help shape a better/more feature rich product.

Con's

• The architecture will change and I don't want to deal with migrations.
• I don't want to deal with support for people wanting to try it.
• Handling differing opinions of technical implementation/features.
• Not learning all the new interesting things myself.

What's your experience when creating a brand new open source project and when do you press that button and make it public?

About the project

This has been an itch I've wanted to scratch for sometime. I want a cross platform bookmark system, both for regularly accessed sites and to use as a read it later list. I don't want the complexity of Pocket for the latter and sites like MyBookmarks.com don't have mobile app's. Every open source project I've looked at has been poor/abandoned. I also don't want ongoing running costs as I won't be monetising this so self hosted server is the way to go.

What I have so far

• A .net core web api/db in a docker container
• A JS Chrome extension to view/add/maintain bookmarks

What I plan to do

• iOS SwiftUI app (Inexperienced but interested)
• Android app (Experienced)
• Web frontend, probably Vue (Inexperienced)
• Firefox extension (Inexperienced)
• Edge extension (post chrome) (Inexperienced)
• Mac app and Safari extension (Inexperienced but interested)

The technology choices are based on what I have dealt with in the past or am keen to learn. I prefer native experiences rather than cross-platform compromises.