Are headless CMS options something that developers can customize for their own use case? Or no?

(assuming its open source)

Wappler builds Node.js. If I found a Node.js headless CMS project, shouldn’t I be able to open it in Wappler and edit it or build on it for my usecase? Wouldn’t this be like me getting the CRUD operations I need as well as a bunch of other features skilled devs already figured out?

I’ve searched the forum extensively and lol a couple of people said they could whip CRUD apps out in 5 minutes. Regrettably, lol, I am not such a person. It’s why I’m here